Composed of the noun pound note, denoting a banknote worth one pound sterling, and of the suffix -ish, meaning having the qualities of, the informal British-English adjective pound-noteish, also pound-notish, means affected, pompous.
The image is probably of someone who considers themself to be worth a pound sterling when they are actually worth less. This is supported by the following from The Seal (London: Hodder & Stoughton Ltd, 2002), by the British author Meg Hutchinson, writing as Margaret Astbury:
The House of Jarreaux—pound-notish his mother would have called that, pretending to be worth a pound when it wasn’t worth tuppence.
‘Wanderer’ used the adjective pound-notish in the following interesting passage from his column It occurs to me, published in the Lynn News & Advertiser (King’s Lynn, Norfolk, England) of Tuesday 1st May 1973—Surbiton is an affluent neighbourhood in London:
When I was freshly commissioned at the age of twenty, I was an ordinary lad with a Lancashire accent tinged with Liverpool nasal. Regional accents are now fashionable, but at that time, though we rated the southerner a sissy, deep down we were conscious of our accent against the slow, refined, “posh” or “pound-notish” BBC announcer drawl that the lad from Surbiton used daily.
My father seldom criticised me, and in my early days in officer’s uniform the pride came out of his eyes like banners. But one day he took me aside. “Ee, I hope you don’t mind me mentioning it, lad, but you’re full of ‘ectuallies’, and ‘awfullies’, and ‘orfs’ these days. Be yourself, lad, it’s what you are and not what you sound like that matters.”
He was right, and when I took his advice I stopped feeling accent-inferior. But I remember the incident whenever I hear a speech by a jumped-up local dignitary, late party worker who kept his nose clean, doing what I did at twenty, little realising that, with every sentence, his verbal slip is showing.
The earliest occurrences of the adjective pound-noteish, also pound-notish, that I have found are as follows, in chronological order:
1-: From Notes by the Chiel, published in the Evesham Standard and West Midland Observer (Evesham, Worcestershire, England) of Saturday 8th October 1927:
WHAT WE WANT TO KNOW.
Who are the three Evesham girls who let the cat out of the bag in a Birmingham tram? Do they speak in a more “pound-noteish” manner now?
Who is the Evesham youth who swears that he has seen a ghost in the Abbey Park hovering round the tank? Is it a fact that he will not venture along Waterside after dark?
2-: From one of the unconnected paragraphs making up the column Miscellany, published in the Runcorn Weekly News and District Reporter (Runcorn, Cheshire, England) of Friday 12th September 1930:
The conductor who used the “pound-notish” tone to some kiddies when warning them to be careful getting off the bus, had the perfect answer when one of the little tots, drawing herself up to her full height, said in similar tone: “I know all about that; I have been on buses before!”
3-: From The Wayward Nymph, by C. Hedley Barker, published in the Los Angeles Times (Los Angeles, California, USA) of Sunday 21st April 1935—“they” denotes Lucy and her husband:
An uncle of hers died in New Zealand, so that she found herself with three pounds a week pin-money. Nothing would please her now but Surbiton where the quality lived and the houses had a gate marked “tradesmen.” So to Surbiton they went, where they had a front garden as neat as you like with a sunk pond five-by-five, and electric waffle-irons. […]
[…] Lucy, a rare one for picking things up, schooled herself in pound-notish talk of the Surbiton brand and learned how to crook her finger round a cup of tea and kept a sharp eye on film-star etiquette at dinner parties. And when she walked out she looked a lady from the tips of her toes to the crown of her proud-set head, which is mortal curious doings for a lass who was born to a farm laborer.
4-: From the column Pull Up a Chair, by Neal O’Hara, published in several U.S. newspapers on Monday 11th November 1935—for example in The Morning Post (Camden, New Jersey, USA):
My word: “Pound-notish” is British slang for “swell.”
5-: From The Gilt Kid (London: Jonathan Cape, 1936), a novel set in London, by the British author James Curtis (born Geoffrey Basil Maiden – 1907-77):
Maisie spoke. Her pound-noteish voice both annoyed and amused the Gilt Kid. She looked fine, though. Innocent and empty-headed. It was a shame to have her running around with old mugs like this bedbug-fellow. These old boys with the dough always grabbed the best janes—the dirty old cowsons.
‘Shall we dance, Maisie?’ he asked.
She turned to Bedborough.
‘Do you mind if we dance, Biffs?’ she inquired.
‘Do, my dear, do,’ he beamed.
‘What did you call old Bedbug just now?’ asked the Gilt Kid as they took the floor.
‘Biffs,’ she answered. ‘He likes me to call him that. It was his monicker at Oxford College or some place.’
Jealousy and savage contempt blended in the Gilt Kid’s tone.
‘I won’t have you using that bad language.’
‘You know what it means all right, so don’t get all pound-noteish.’
6-: From a letter to the Editor, published in the Leicester Evening Mail (Leicester, Leicestershire, England) of Thursday 16th January 1947:
SIR,—A little investigation has taught me how to combat the under-the-counter methods of retailers in a Leicester suburb. Having tried unsuccessfully to get such things as points goods and oranges from the shopkeepers of my neighbourhood (they used to crawl for my custom seven years ago; they’ll be crawling again before they get much of it), I tried other districts.
In parts of Leicester where the pound-notish would scorn to go and the toffee-nosed would not dare to be seen, I was able to purchase in small shops canned goods as much as my points would permit, bitter oranges and lemons for making marmalade, and Jaffas for dessert. I experienced good manners from the shopkepers [sic] into the bargain.
I do not think a buyers’ strike would do much good in this country, but I think the Leicester housewife and her family might fare better if the housewifely function were exercised in looking for the household needs, instead of having them “on tap” at the discretion of a temperamental retailer.