There are two popular stories about Nerd's origin.

The first is that it come from Dr. Seuss's If I Ran the Zoo, in which appears a creature called a "nerd."

This book was published in 1950: " I'll sail to Ka-Troo And Bring Back an It-Kutch, a Preep and a Proo, A Nerkle, a Nerd, and a Seersucker, too!"

The second is that it is a variation on the name of ventriloquist Edgar Bergen's (Candace's father) dummy, Mortimer Snerd.

Either could be correct. There is no cite of the term prior to its 1950 appearance in the Dr. Seuss book. The earliest cite of the current usage is from 1951. Lighter, however, cites a 1941 use of the nickname Mortimer Snerd to refer to a technical, brainy type of guy.

" I discussed the P-40 flying characteristics with 'Mortimer Snerd' Shilling." --C.R. Bond & T. Anderson, Flying T. Diary

Chapman suggests that it is from surfer or hot-rodder lingo and could be a derivation of nerts or nuts. The OED2 suggests both the Dr. Seuss explanation and the possibility that it could be a euphemism for turd. Lighter plumps for the Dr. Seuss origin, despite the 1941 quote. Although it does admit that nerd could have been influenced by Bergen's puppet. The evidence appears to be against the Mortimer Snerd explanation, chiefly because the original sense of nerd was a stupid or obnoxious person.

No cites of it meaning a brainy individual or an industrious student appear until the mid-1970s. Likewise the Dr. Seuss explanation seems doubtful because a one year transition from an obscure, mythical, children's book creature to stupid person seems awfully fast. So in the end, like many words that appear in these pages we just don't know where it came from.

Thanks are do to: www.wordorigins.org