Green’s Dictionary of Slang

maw-worm n.

a hypocrite; also attrib.

[1768		I. Bickerstaff Hypocrite II:vi: Sir, Mr Maw-worm is without [...] Hush, friend Maw-worm, not a word more].
[1824		Morn. Post (London) 27 Apr. 3/1: Theatre Royal Drury-Lane [...] the Comedy of the Hypocrite. Doctor Cantwell, Mr Dowton; Maw-worm, Mr Liston].
1827		Egan Anecdotes of the Turf, the Chase etc. 165: Maw-worm [a horse] was no hypocrite, and did his best to win.
1831		Peter Pendergrass Sr. Magdalen Report 9: He had four lines which Mawworms ought ot know.
1833		‘The Parson’s Wife’ in Rummy Cove’s Delight in Spedding & Watt (eds) Bawdy Songbooks (2011) III 109: While Mawworm he had gone to pray, / He left his wife at home, they say, / Who very naughty pranks did play.
1842		Lincs. Chron. 11 Feb. 4/5: One half of these Maw-worms being in league with the pick-pockets, and deserving to be in Newgate.
1842		Whip & Satirist of NY & Brooklyn (NY) 7 May n.p.: These literary Mawworms advocate pulling up the pavement.
1848		Sinks of London Laid Open 72: ‘Yes!’ snivelled a street-preacher [...] who could scarcely hold up his head for strong drink, ‘we are now entering upon the Lord’s day.’ [...] ‘It is so, old Mawworm, and you had better go to bed.’.
1851		Era (London) 5 Jan. 3/3: Out upon such Mawworm sanctity and conventicle ‘slang!’.
1855		‘Sunday Trading Bill’ in C. Hindley Curiosities of Street Lit. (1871) 115: The mawworms seem to try, I’m sure / Each way they can to crush the poor.
1868		Sportsman 28 Jan. 2/1: Notes on News [...] The gang of maniacal mawworms.
1871		‘George Eliot’ Middlemarch I 30: A man naturally likes to look forward to having the best. He would be the very Mawworm of bachelors who pretended not to expect it.
1879		Reynolds’s Newspaper 16 Feb. 3/3: We ourselves have passed severe judgment [...] upon the moleish Mawworms who dug it out of its place of corruption.
1891		Licensed Victuallers’ Gazette 17 Apr. n.p.: Superintendent S – is no mawworm, And it must have gone very much against the grain [F&H].

In derivatives

maw-wormy (adj.)

pessimistic, fault-finding, nagging.

1885

Entr’acte 6 June in Ware (1909) 174/2: Augustus Harris insisting on Carl Rosa accepting the wreath thrown on the stage last Saturday night was a delicious and touching spectacle. Here is a glorious subject for one of our figure-painters. Without being mawwormy, I fail to see why a wreath should be presented to any man who makes a business of giving opera.