Green’s Dictionary of Slang

tipsy, slightly drunk.

1833		Stamford Mercury 13 Jan. 2/2: A man known as Lumpy Taylor who has long been a trouble to police, owing to his drunken and aggressive habits.
1834		Morn. Chron. 8 Aug. 4/5: ‘Was the defendant sober?’ ‘Why, I think both him and I were a little lumpy’.
1841		Northampton Mercury 9 Jan. 4/1: Wasn’t I precious lumpy! but it is all the fault of the new year.
1844		Lancaster Gaz. 6 Apr. 4/3: I often feel a palpitation of the heart and a headache, without having been a bit lumpy.
1853		Dickens ‘Slang’ in Household Words 24 Sept. 75/2: For the one word drunk [...] moony, muddled, muzzy, swipey, lumpy, obfuscated [etc.].
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 15/1: And his lush loved much for to swill / One day he got rather lumpy.
1861		Melbourne Punch ‘City Police Court’ 3 Oct. 234/1: The Mayor. – What’s the name of the lug chovey in which you lumbered the prop? Prisoner. – It wasn’t lumbered at all, your honor’s lordship. She sold it for a madza caroon in a lush crib, and got lumpy with the dibbs.
1873		Sl. Dict.
1881		Shields Dly Gaz. 10 Jan. n.p.: For the one word drunk [...] we find mops and brooms [...] moony [...] swipy, lumpy [...] on the ran-tan.
1902		Ade Girl Proposition 25: The Lumpy Ones who never go all the way around with the Powder Puff.
1911		B. Fisher Mutt & Jeff 29 Nov. [synd. cartoon] Now after these big games the college boys usually get lumpy.