Green’s Dictionary of Slang

1. (orig. US campus) a fool, an idiot, an unpleasant person.

1900		E.H. Babbitt ‘College Words and Phrases’ in DN II:i 69: wad, n. 1. A queer, unattractive person. 4. An unpopular person.
1957		(con. 1944) A. Myrer Big War 346: That creeping, conniving, brown-nosing wad of braid.
1987		G.A. Fine With the Boys 171: Boys call each other a [...] gay or gay wad.

2. (US campus) a sexually aggressive man.

1979

Eble Campus Sl. Mar. 7: wad – sexually aggressive male.