The noun parlour is based on the French verb parler, meaning to speak, to talk. The primary meaning of this noun is: a room in a monastery or convent that is set aside for conversation.

The noun parlour then came to be also applied to:
– (in a private house) a living room, especially one used for the reception of guests;
– (in an inn or public house) a room, more private than the taproom or saloon, where people may converse.

The last two meanings gave rise to parlour, as an attributive modifier, used derogatorily of:
– a person claiming to be committed to a cause but not actually involved in the achievement of that cause;
– the claimed commitment to a cause without actual involvement in the achievement of that cause.
—Cf. also ‘parlour socialist’ | ‘parlour socialism’ and ‘armchair’ (attributive modifier).

PARLOUR PATRIOT

It seems that parlour patriot (American English parlor patriot) is the earliest of the phrases in which parlour is a depreciative attributive modifier.

These are the earliest occurrences of parlour patriot that I have found, in chronological order:

1-: From a letter that the English poet, critic and philosopher Samuel Taylor Coleridge (1772-1834) wrote on 6^th February 1797 to the English political reformer, author, orator and elocutionist John Thelwall (1764-1834)—as published in Letters of Samuel Taylor Coleridge (Boston and New York: Houghton, Mifflin and Company, 1895), edited by Ernest Hartley Coleridge:

Of your scheme of a school, I approve it; and fervently wish, that you may find it more easy of accomplishment than my fears suggest. But try, by all means, try. Have hopes without expectations to hazard disappointment. Most of our patriots are tavern and parlour patriots, that will not avow their principles by any decisive action; and of the few who would wish to do so, the larger part are unable, from their children’s expectancies on rich relations, etc., etc.

2-: From the following paragraph published in the Rutland Herald (Rutland, Vermont, USA) of Thursday 29^th April 1847:

Army Promotions.—The Administration has a way of doing things which makes itself hated and despised. There are experienced, capable and meritorious officers who have been gallantly upholding the honor of the country in the battle fields of Mexico, whose services and patriotism entitle them to promotion. But those men, though covered with wounds received in fighting President Polk’s battles, are passed over and neglected! But Caleb Cushing, a sunshine, parlor Patriot, who in a Dinner Speech at New Orleans, insulted the memory of the lamented Lieutenant Colonel Clay, and outraged the feelings of a bereaved Father, is rewarded with the appointment of Brig. General!—Alb. Eve. Jour.

3-: From the Pennsylvania Telegraph (Harrisburg, Pennsylvania, USA) of Tuesday 18^th May 1847:

Gen. Taylor is honorable; he is fearless; he is patriotic, intelligent and brave. He shrinks from the contamination as from pestilence. His popularity is his own, his fame is his country’s: hewn out by his own arm in its service. His laurels are those of fame, earned in protecting the interests and scourging the enemies of the republic: not won by bar room politicians, and parlor patriots and bestowed as passports to offices of peculation.

The earliest occurrence of the phrase parlour patriotism that I have found is from The Saturday Express (Lancaster, Pennsylvania, USA) of Saturday 26^th June 1852:

Blood and Powder Patriotism.

On more than one occasion have we spoken of the foolish and dangerous practice of firing cannon on the Fourth of July, and other festive occasions. And just so long as the history of these ‘memorable occasions’ continues to be written in blood and mourning, we will continue to speak, write and print in denunciation of the cruel fashion of killing people on patriotic principles.
Is human life a toy that men should play with it, dangling the immortal soul over the precipice of eternity? Are the happiness of wives, the welfare of children, the peace of dear friends, of so little value that they may be made widows, orphans, and desolate, in a single hour, merely to gratify the parlor ‘patriotism’ and starched ‘glory’ of a few paper and ink, or smoke and powder heroes? So it would seem.

The earliest occurrence of the phrase bar-parlour patriot that I have found is from the following paragraph published in The Rhyl Advertiser (Rhyl, Flintshire, Wales) of Saturday 14^th May 1881:

The Sunday Closing Bill is too drastic a measure for a few pot-house politicians and bar-parlour patriots; hence they are getting up a petition to parliament for the exemption of Rhyl. These advocates of Sunday tippling, who tell us how deceptive and misleading petitions are when got up by other people, especially “canting hypocrites,” appear to have no scruples when getting up a petition themselves. Signatures are now being obtained from anybody, regardless of age or residence. People living in various parts of the Principality and of England have been asked to sign for Rhyl to be made the rendezvous of Sunday fuddlers. Their failure may be safely predicted from the fact that out of 78,000 ratepayers in North Wales, no less than 75,510 have declared in favour of the Bill; and 29 members of Parliament out of the 30, have done likewise. Sunday sale of drink is doomed.