Green’s Dictionary of Slang

St Lubbock n.

a drunken riot.

1909

J. Ware Passing Eng. of the Victorian Era 213/2: St Lubbock (Lower London, 1880 on). An orgy, a drunken riot. From the August Bank Holiday, the first Monday in the month, chiefly invented, in the parliamentary sense, by Sir John Lubbock. The tendency on the part of the more violent holidaymakers produced the satirical ‘St’, and its accompanying meaning.

In compounds

St Lubbock’s day (n.) (also feast of St Lubbock)

a bank holiday.

1876		Western Times 8 Aug. 5/2: ‘I care not who makes the laws provided I make the holidays,’ quoth the Statesman. This St Lubbock proves that the Statesman was a knowing card, for people [...] turned out to enjoy the day.
1883		Bristol Magpie 22 Feb. 5/1: [T]he beneficent ‘bank’ holiday, on the first Monday in August, popularly known as ‘Saint Lubbock’ .
1885		Leicester Chron. 4 Aug. 8/2: ‘Thank St Lubbock for Bank Holidays’ is as sound a saying as a good many that are more pretentious.
1887		Sheffield Wkly Teleg. 6 Aug. 5/1: Bank Holiday, or ‘St Lubbock’s Day,’ as the first Monday in August [...] increases in popular favour with the working classes.
1899		Daily Tel. July in Ware (1909) 213/2: The feasts of St Lubbock—i.e., Bank Holidays—established in consequence of the exertions of Sir John Lubbock, M.P. (afterwards Lord Avebury), in 1871, are regarded with the highest favour. Their influences upon the commercial world and whole community have been remarkable.
1909		J. Ware Passing Eng. of the Victorian Era (213/2) St Lubbock, Feasts of (Public, 1871 on). Bank holidays as established by law – Easter Monday, Whit Monday, first Monday in August and Boxing Day, 26th December. From Sir John Lubbock’s Act, 1871, by which the first, second, and fourth were made legal, and the third created.
1984		Partridge DSUE (8th edn) 1007/1: ca. 1880–1914.