Well, the whole point of the OED is to be comprehensive, no? Is "eit" or "d'oh" in there?
eit is not.

doh is:

Expressing frustration at the realization that things have turned out badly or not as planned, or that one has just said or done something foolish. Also (usu. mildly derogatory): implying that another person has said or done something foolish (cf. DUH int.).

1945 T. KAVANAGH It's That Man Again (B.B.C. radio script: 8th Ser. No. 166), Tom: Yes, out of the nest-Diana: What nest? Tom: In those whiskers-Diana: Dooh! Its [sic] no good talking to you. 1945 T. KAVANAGH It's That Man Again (B.B.C. radio script: 8th Ser. No. 167), Diana: The man I marry must be affectionate and call me ‘Dear’-Tom: Oh you're going to be a stag's wife-Diana: Doh! Tom: Same thing. 1952 A. BUCKERIDGE Jennings & Darbishire xii. 183 ‘Doh!’ An anguished gasp of exasperation rang out loud and clear as Mr Wilkins found his voice again. 1989 Beano 11 Feb. 23 (caption) [Speaker is a man who is knocked against a bus stop.] Doh! 1991 Chicago Tribune (Nexis) 15 Nov. (Friday) H, ‘The movie had one good point: It wasn't the worst movie I've ever seen.’ ‘It was the worst movie I've ever seen.’ ‘Doh!’ 1993 HP Professional (Nexis) July 28 Along their long path ISO sort of missed local area networks and network management, which gave the market over to TCP/IP and related technologies. As Homer Simpson would say: ‘Doh!’ 1996 A. FEIN et al. Simpsons Comics strike Back! 14/2 ‘Look out, you dern fool! You're gonna cut off your...’ ‘D'oh!!!’ 1998 N. JONES Hollyoaks (Mersey TV transmission script) Episode 256. 44 Cindy: What are we doing here, anyway? Paul: Doh! Use your head, eh?
See The Story of Eit for the origins. It's basically an exclamation in reaction to misfortune, or an instance of misfortune itself.

Almost-antonym: "Pock", which has been translated as "the sound of the pinball machine of the universe giving you a free ball" -- basically, an unexpected small win.
As far as I can tell, it is an MIT-ism, and limited even there. I'm just doing my part to spread the meme.
I expect the OED lexicographers are as aghast as you are. They don't make the language, they just document its common abuses.
You can probably partly blame Virgin Airlines though: their inflight shopping catalogue titles the jewellery and shiny stuff section with "Bling-Bling".
I expect the OED lexicographers are as aghast as you are. They don't make the language, they just document its common abuses.

Do you still know someone who works on the OED website? (That was you, wasn't it, who knew someone?) Is he/she still unwilling to be bribed? :)

You can probably partly blame Virgin Airlines though: their inflight shopping catalogue titles the jewellery and shiny stuff section with "Bling-Bling".

... Oh my. Ow.
I'm sure all OED staff have the highest professional ethics and would not possibly consider such an action.
(pronounced: We tried to get him to easter-egg the OED, he wouldn't :) )

The reason for blaming Virgin is that the OED works mainly from printed published references when it comes to deciding whether to put a word in the Dictionary, though once they have decided to do so, they may use other instances of common usage such as online references to refine their definition.
HighWire hosts the OED online.

No, really.

This doesn't mean I have access to it, but it has been tempting to see if I could add things. :)