The noun omelette designates a dish of beaten eggs cooked in a frying pan and served plain or with a savoury or sweet topping or filling.

This noun is an early-17^th-century borrowing from French omelette, which is attested in the mid-16^th century and is an alteration of amelette. The change in the initial vowel from a to o occurred in southern French under the influence of forms of œuf, meaning egg (there were in Middle French forms such as œufmollette, attested in 1576).

The form amelette, attested in 1480, is a variant, with metathesis, of an unattested Middle-French noun alemette, a secondary form of alumette, which is attested in the late 14^th century and is itself in turn a variant, with suffix substitution, of alumelle, alemelle, meaning blade of a knife or of a sword and by extension omelette because of the flattened shape of the dish. (Similarly, the French noun flan means both disk of metal before stamping and by extension custard cake. Of Germanic origin, it is related to German Fladen, flat cake, and to English flat.)

The form alemelle is in turn a variant, with metanalysis of the definite article la, of lemelle, that is to say that la lemelle, meaning the blade, was misinterpreted as l’alemelle.

The word lemelle is itself an earlier form of lamelle, meaning short thin blade, from classical Latin lamella, a small thin plate of metal, diminutive of lamina.

The first known mentions of omelettes are found in recipes given by the anonymous author of Le Ménagier de Paris (The Household Book of Paris – circa 1392-94) in which a (probably fictional) wealthy elderly Parisian bourgeois addresses his 15-year-old bride. This is one of those recipes (the obsolete noun arboulastre, ultimately derived from Latin herba, denoted an herbed dish):

     literal translation of the Middle-French text:
An ‘arboulastre’ or two of eggs. Take costmary, two leaves only, and of rue less than half that or none at all, for know that it is strong and bitter; wild celery, tansy, mint and sage, of each four leaves or less, for each is strong; marjoram a little more, fennel yet more, and parsley even more. But as for vegetable, chard, violet leaves, spinach and lettuce, clary, each in equal amount, so that of all you have two good handfuls; select and wash in cold water, then press and remove all the water, and grind up two pieces of ginger. Then put in a mortar two or three times your herbs with the said ground ginger, and grind one with the other. And then take sixteen eggs well beaten, yolks and whites, and grind and mix [them] in the mortar with what is said, then divide in two, and make two thick omelettes which will be fried in the following manner. First, heat thoroughly your pan with oil, butter or such other grease as you’ll wish, and when it is quite hot all over, and especially towards the handle, mix and spread your eggs on the pan and turn [them] often with a spatula, then sprinkle some good grated cheese on top. And know that it is done in this manner because he who would grind the cheese with the herbs and eggs, when he would try to fry his omelette, the cheese which would be at the bottom would stick to the pan; and so he does with his egg omelette, he who mixes the eggs with the cheese. And for this reason one must first put the eggs into the pan, and put the cheese on top, and then cover with the edges of the eggs; and otherwise [they] would stick to the pan. And when your herbs are fried in the pan, you give a square or round shape to your arboulastre and eat it neither too hot nor too cold.
     original text:
Une arboulastre ou deux d’œufs. Prenez du coq deux fueilles seulement, et de rue moins la moitié ou néant, car sachez qu’il est fort et amer : de l’ache, ténoisie, mente et sauge, de chascun au regart de quatre fueilles ou moins, car chascun est fort : marjolaine un petit plus, fenoul plus, et percil encores plus ; mais de porée, bettes, feuilles de violettes, espinars et laitues, orvale, autant de l’un comme de l’autre, tant que de tout vous aiez deux poignées largement : eslisez et lavez en eaue froide, puis les espraignez et ostez toute l’eaue, et broyez deux cloches de gingembre ; puis mettez ou mortier à deux ou à trois fois vos herbes avec le dit gingembre broyé, et broyez l’un avec l’autre. Et puis aiez seize œufs bien batus ensemble, moyeux et aubuns, et broyez et meslez ou mortier avec ce que dit est, puis partez en deux, et faites deux alumelles espesses qui seront frites par la manière qui s’ensuit : premièrement vous chaufferez très bien vostre paelle à huille, beurre ou autre telle gresse que vous vouldrez, et quant elle sera bien chaude de toutes pars, et par espécial devers la queue, meslez et espandez vos œufs parmy la paelle et tournez à une palette souvent ce dessus dessoubs, puis gettez de bon frommage gratuisé pardessus ; et sachez que ce est ainsi fait pour ce qui brayeroit le frommage avec les herbes et œufs, quant l’en cuideroit frire son alumelle, le frommage qui seroit dessoubs se tendroit à la paelle ; et ainsi fait-il d’une allumelle d’œufs, qui mesle les œufs avec le frommage. Et pour ce l’en doit premièrement mettre les œufs en la paelle, et mettre le frommage dessus, et puis couvrir des bors des œufs : et autrement se prendroient à la paelle. Et quant vos herbes seront frites en la paelle, si donnez forme quarrée ou ronde à vostre arboulastre et la mengiez ne trop chaude ne trop froide.

In English, omelette is first recorded in A Dictionarie of the French and English Tongues (1611), by Randle Cotgrave:

– Omelette. An Omelet, or Pancake of egges; Looke Aumelette.
– Aumelette d’œufs. An Omelet; or pancake made of egs.
Vireurs d’aumelettes. Idle fellowes, uaine companions, or, cotqueanes; people that busie themselues, or loue to be medling, in base, or unworthie imployments.

The proverb one can’t make an omelette without breaking eggs and variants means it is not possible to accomplish something worthwhile without adverse effects elsewhere. It is after French on ne peut pas faire d’omelette sans casser des œufs and variants.

The French proverb was recorded in Dictionnaire universel françois et latin contenant la signification et la définition tant des mots de l’une & de l’autre langue, avec leurs différens usages, que des termes propres de chaque état & de chaque profession, known as Dictionnaire de Trévoux:

     (1721 edition)
Aumelette, d’autres écrivent omelette. […]
On dit proverbialement, on ne fait point d’aumelette sans casser des œufs, pour marquer qu’il y a certaines chôses absolument nécessaires pour l’éxécution des affaires.
     translation:
Aumelette, others write omelette. […]
It is proverbially said, one does not make an omelette without breaking eggs, to indicate that there are certain things absolutely necessary for the execution of affairs.

(This dictionary also recorded the form amelette.)

The first known occurrence of the proverb in English is in The Monthly Magazine, or British Register of April 1796; François de Charette (1763-96) was a French Royalist soldier and politician, one of the leaders of the war in Vendée against the revolutionary regime:

Deaths Abroad.
On the 9^th of March, at Nantes, the celebrated general Charette, soul of the civil war in France. Having been taken on the 7^th instant, by the adjutant-general Travot, he was instantly conducted to Angers. […] They said to him, you have made us lose a great many men. “Ah! One cannot make pancakes without breaking eggs.”

This probably translates Charette’s words literally.