Green’s Dictionary of Slang

1. the professing of Roman Catholicism.

1837

Caledonian Mercury 10 Aug. 4/2: What would become of their own Protestant religion but for the movement? Only for it, they would all now be craw-thumping and blessing themselves.

2. religiosity.

1841		Cork Examiner 1 Nov. 4/4: A certain Preacher, who frightened his audience into craw-thumping when he expressed, Diabhal mor [etc.].
1846		Bradford Obs. 3 Sept. 7/3: And night and day, from that day out, he so the Virgin yeas’d / With pray’rs and sighs and craw-thumping at length she got appeased.
1885		Bulletin (Sydney) 31 Jan. 20/1: Run him in, too, for in spite of all his craw-thumping and Psalm-snuffling deeds, his pile is made up of ‘crime and immorality,’ and he is just as great a vagrant as the veriest ‘bummer’ or magsman in the land.
1894		Freeman’s Jrnl 31 Jan. 3/9: Every step was taken with craw-thumping.