Green’s Dictionary of Slang

1. a member (usu. an undergraduate) of Cambridge University.

1750		F. Coventry Hist. of Pompey Little (1785) II 68/1: The young Cantab who now took possession of him, had come up to London.
1799		Sporting Mag. Apr. XIV 39/2: [heading] Letter from a Young Cantab to His Friend.
1803		‘A Pembrochian’ Gradus ad Cantabrigiam Dedication: Not owing obligations, which, by the way, I should have been very happy in doing, to Cantabs of greater experience.
1821		Byron Don Juan canto III stanza 126: And I grown out of many ‘wooden spoons’ / Of verse (the name with which we Cantabs please / To dub the last of honours in degrees) .
1832		Egan Bk of Sports 302: On that classic ground he was hailed as a man of science by several of the cantabs.
1856		B.H. Hall College Words (rev. edn) 58: cantab. Abridged for Cantabrigian [...] A student or graduate of the University of Cambridge, Eng.
1864, 1867, 1870		Hotten Sl. Dict.
1876		H.E. Malet Annals of the Road 90: [T]he celebrated young cantab, Mr. Stevenson, who did so much [...] to elevate the science and heighten the tone of the thing, bringing Corinthian and coachman more on a level.

2. a member (usu. an undergraduate) of Harvard University in Cambridge, Mass.

1834

Knickerbocker (N.Y.) III 301: Nick was made a cantab at Harvard [DA].