> nerd
> 
> nerd nrd. slang (chiefly U.S.). Also nurd. Of uncertain origin:
> sometimes taken as a euphemistic alteration of turd (see, for
> example, D. L. Gold in Comments in Etymol. (1983) XII. 27), though
> perh. simply derived from the children's book character cited in
> quot. 1950. An insignificant or contemptible person, one who is
> conventional, affected, or studious; a `square', a `swot'.
> 
>    * 1950 Dr. Seuss If I ran Zoo 49 And then, just to show them,
>      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!
> 
>    * 1957 Sunday Mail (Glasgow) 10 Feb. 11 Nerd-a square.
> 
>    * 1968-70 Current Slang (Univ. S. Dakota) III-IV. 88 Nurd,
>      someone with objectionable habits or traits; an affected
>      person... An uninteresting person, a `dud'.
> 
>    * 1971 Observer 23 May 36/3 Nerds are people who don't live
>      meaningful lives.
> 
>    * 1979 Tucson Mag. Feb. 21/2 Graffitti... Possibly the world's
>      largest depository of nerd art.
> 
>    * 1980 Internat. Herald Tribune 21 July 16/1 At MIT, `nerd' is
>      spelled `gnurd'... Gnurds study all the time because they like
>      to.
> 
>    * 1983 Truck & Bus Transportation July 129/1 When loose-brained
>      nurds crack up the top arrangements of a man o' my calibre, I
>      got no union t' thump them nurds with.
> 
>    * 1984 Guardian 17 June 21/2 His..rage..is directed at the whole
>      of American society for its bland, tasteless, pretentious,
>      illiterate `nerd-pack' mentality.
> 
>    * 1986 M. Howard Expensive Habits 107 He feels..like a total nerd
>      in his gentleman's coat with the velvet collar.
> 
> Hence
> 
> nerdy
> 
> 'nerdy a., characteristic of a `nerd'.
> 
>    * 1978 N.Y. Times 25 Jan. d18 (Advt.), The nerdiest nerds on TV
>      are really smart cookies.
> 
>    * 1979 New Yorker 19 Feb. 92 The nurdier clients want foil... `If
>      the potatoes are in foil, that's gourmet.'
> 
>    * 1982 Guardian 26 Oct. 8/8 She goes for a really tubular type of
>      dude, the kind of hot babe with a cute butt who isn't all hairy
>      and gross but isn't any nerdy zod either.
> 
>    * 1987 N.Y. Times Mag. 31 May 46/3 Our wives..agreed that we had
>      been pretty nerdy back then.