Green’s Dictionary of Slang

1. a graduate, lit. or fig.; thus undergrad.

1871		L.H. Bagg Four Years at Yale 45: Grad, abbreviation for graduate.
1893		W.K. Post Harvard Stories 129: An old grad. attains his title as soon as he ceases to be a very young grad.
1900		E.H. Babbitt ‘College Words and Phrases’ in DN II:i 38: grad, n. Graduate.
1902		Bulletin (Sydney) 11 Oct. 13/2: Many addresses in Latin and a few in French were delivered; and you might notice that the old-time grads. [...] [were] seizing the occasion to applaud violently to show that they ‘understood every word’ of the Latin oration.
1912		Ade Knocking the Neighbors 160: By 6:45, four old Grads, with variegated Belshazzars, were massed together in the Egyptian Room.
1924		P. Marks Plastic Age 68: He was darned lucky to have a father who was a college grad and could put him wise.
1935		J. Conroy World to Win 119: Most of the older grads were talking angrily about the report that the university authorities were going to raze the dome unsafe.
1938		F.D. Sharpe Sharpe of the Flying Squad 319: Undergrads with scarves round their necks.
1956		‘Ed Lacy’ Men from the Boys (1967) 16: Who isn’t a college grad these days with the G.I. Bill?
1958		H.S. Thompson letter 23 Jan. in Proud Highway (1997) 102: One is a Harvard grad, one a Yale grad.
1981		(con. 1967) P. Conroy Lords of Discipline 447: All Institute grads.
1988		in D. & C. Schneider Sound Off! 171: Three females [...] got turned down, one of whom was the honor grad.
1992		R. Marcinko Rogue Warrior (1993) 254: Mugsy was another Academy grad.
2000		Guardian Editor 4 Feb. 13: A 30-year-old business grad.
2006		C. Carr Our Town 272: Thompson let me know he was their ‘only college grad’.

2. attrib. use of sense 1.

1925		S. Lewis Arrowsmith 32: So many of the English grad students just want to make money teaching.
1975		L. Rosten Dear ‘Herm’ 11: ‘Hermie the Klitch,’ about whom our grad book said: ‘Keep your eyes on this cowboy!’.
1976		in R. Yates Easter Parade (2003) 50: I could’ve sworn you were a grad student.
1989		(con. 1960s) M. Kingston Tripmaster Monkey 76: He’s the only Chinese-American of his generation not in grad school.
1992		M. Leyner Et Tu, Babe (1993) 43: ‘Have you finished graduate school?’ ‘Yeah, I finished grad school last June.’.
2001		G. Pelecanos Right As Rain 248: This place has financed half my grad school tuition so far.
2015		S. King Finders Keepers (2016) 51: His mother was in New Jersey [...] lecturing to grad students.

3. in non-academic contexts, a person who has ‘graduated’, e.g. an ex-convict.

1917		A. Baer Giants in Hot Water 23 May [synd. col.] To-day’s contest will be between the old grads and the undergraduates. Doyle, Merkle [...] and Demaree are old polo Ground students.
1939		W. Winchell On Broadway 3 Feb. [synd. col.] Eva Ortega [...] is a major Bowes program grad.
1946		Mezzrow & Wolfe Really the Blues [dedication] To all the junkies and lushheads in two-bit scratch-pads, and the flophouse grads in morgue iceboxes. (R.I.P.).
1950		Goldin et al. DAUL 86/1: Grad. An ex-convict. (Usually preceded by the name of prison, as, ‘A Sing Sing grad,’ etc.).
1966		H.S. Thompson Hell’s Angels (1967) 37: A third of these are Hell’s Angels in name only ... old grads, gone over the hump to marriage and middle age.