According to Today I Found Out http://www.todayifoundout.com/index....erd-came-from/

Before “geek”, “nerd”, “dork”, etc, the proper terms for these same ragamuffins were “Dewdroppers”, “Waldos”, and “Slackers”. Other common old slang words that were somewhat similar in meaning: pantywaist, oil can, drip, stinkeroo, mullet, roach, schnookle, kook, dimp, dorf, squid, auger, square, Joe Zilch, and dudd.

Who Gnu? Actually, I can remember being called many of these names. Maybe not oil can, but many of the others.