From 19th-century British thieves' cant, of uncertain origin. Perhaps from *tarsh, a metathetic alteration of trash; or from toss.
Sense of nonsense possibly influenced by tush (“nonsense! tsk tsk!”) attested from 15th century.
Meanings
(UK, obsolete, slang, uncountable) Copper; items made of copper.
The sewer-hunters were formerly, and indeed are still, called by the name of "Toshers," the articles which they pick up in the course of their wanderings along shore being known among themselves by the general term "tosh," a word more particularly applied by them to anything made of copper. [1851, Henry Mayhew, “Of the Sewer-hunters”, in London Labour and the London Poor; […], volume II (The London Street-folk. Book the Second.), London: [Griffin, Bohn, and Company], →OCLC, page 150, column 2:
(UK, rare, slang, uncountable) Valuables retrieved from drains and sewers.
I am present engaged in fishing for tosh in the sewers of Blastburn. 1974, Joan Aiken, Midnight is a Place, page 164:
Perhaps it helped a man into Parliament, Parliament still being a confused retrogressive corner in the world where lawyers and suchlike sheltered themselves from the onslaughts of common-sense behind a fog of Latin and Greek and twaddle and tosh. 1911, H[erbert] G[eorge] Wells, chapter 5, in The New Machiavelli, London: John Lane; The Bodley Head […], →OCLC:
To think what I've gone through to hear that man! Frightful tosh it'll be, too. 1892 October 26, Oxford University Magazine, number 26/1:
‘Took yeh from the ruined house myself, on Dumbledore’s orders. Brought yeh ter this lot...’ ‘Load of old tosh,’ said Uncle Vernon. 1997 June 26, J. K. Rowling [pseudonym; Joanne Rowling], chapter 4, in Harry Potter and the Philosopher’s Stone (Harry Potter; 1), London: Bloomsbury Publishing, →ISBN:
(UK, countable, qualifier:archaic school slang) A bath or foot pan
We call a tub a tosh. 1905, H. A. Vachell, Hill, section I:
A ‘tosh’ pan... is also provided. 1881, Leathes in C.E. Pascoe, Everyday Life in our Public Schools, ii. 20
(derogatory, slang, uncountable) Easy bowling
Among the recent neologisms of the cricket field is ‘tosh’, which means bowling of contemptible easiness. 1898 June 25, Tit-Bits, 252/3
(UK, humorous, slang, uncountable) Used as a form of address.
'Ere, tosh, you bin at Cha'ham? 1954, E. Hyams, Stories & Cream, section 175:
From 19th-century British thieves' cant, of uncertain origin. Perhaps from *tarsh, a metathetic alteration of trash; or from toss.
Sense of nonsense possibly influenced by tush (“nonsense! tsk tsk!”) attested from 15th century.
Meanings
(UK, obsolete, slang) To steal copper, particularly from ship hulls
Toshing, a cant word for stealing copper sheathing from vessels' bottoms, or from dock-yard stores.
(UK, slang, uncommon) To search for valuables in sewers
You tend to the toshing, let Mester Hobday tend to the dealing. 1974, J. Aiken, Midnight is Place, vi. 180:
(UK, qualifier:archaic school slang) To use a tosh-pan, either to wash, to splash, or to "bath"
‘Toshing’ was the name given to a punishment inflicted by the cadets on any one of their number who made himself obnoxious. The victim, dressed in full uniform, was forced to run the gauntlet of his brother cadets, who, as he passed, emptied the contents of their ‘tosh-cans’ (small baths holding about three gallons of water) over the wretched lad's head. 1883, J.P. Groves, From Cadet to Captain, iii. 227:
He toshed his house beak by mistake, and got three hundred. 1903, J. S. Farmer et al., Slang, VII. 171/1:
From 19th-century British slang tosheroon, from or alongside tusheroon, of uncertain derivation from British slang caroon (“crown, a 5-shilling silver coin”), from Sabir and (originally) Italian corona (“crown”). The term was either derived from or influenced by madza caroon, the British slang for the Sabir and Italian mezzo corona (“half-crown”), possibly under influence from tosh (“copper items; valuables”) above or from the half-crown's value of two shillings & sixpence.
Meanings
(UK, countable, obsolete, slang) A half-crown coin; its value
Here's a tosh to buy yourself some beer. 1961, J. Maclaren-Ross, Doomsday Book, i. v. 63:
tush or tosh. Money: Cockney: late C.19–20. Ex: tusheroon... But H. errs, I believe: he should mean half-a-crown, for tusheroon and its C.20 variant tossaroon (2s. 6d.) are manifest corruptions of Lingua Franca MADZA CAROON. 1961, Eric Partridge, The Routledge Dictionary of Historical Slang:
(UK, countable, obsolete, slang) A crown coin; its value
‘Tush’, for money, would be an abbreviation of ‘tusheroon’, which in old cant, and also in tinker dialect, signified a crown. 1912, J.W. Horsley, I Remember, xii. 253:
Half-a-crown is known as an alderman, half a bull, half a tusheroon, and a madza caroon; whilst a crown piece, or five shillings, may be called either a bull, or a caroon, or a cartwheel, or a coachwheel, or a thick-un, or a tusheroon. 1859, J.C. Hotten, A Dictionary of Modern Slang, Cant, and Vulgar Words:
(UK, archaic, slang, uncountable) Any money, particularly pre-decimalization British coinage