The Collaborative International Dictionary of English v.0.48:

Retch \Retch\ (r[e^]ch or r[=e]ch; 277), v. i. [imp. & p. p.
   Retched (r[e^]cht); p. pr. & vb. n. Retching.] [AS.
   hr[ae]can to clear the throat, hawk, fr. hraca throat; akin
   to G. rachen, and perhaps to E. rack neck.]
   To make an effort to vomit; to strain, as in vomiting.
   [Written also reach.]
   [1913 Webster]

         Beloved Julia, hear me still beseeching!
         (Here he grew inarticulate with retching.) --Byron.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Retch \Retch\, v. t. & i. [See Reck.]
   To care for; to heed; to reck. [Obs.] --Chaucer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

retch
    n 1: an involuntary spasm of ineffectual vomiting; "a bad case
         of the heaves" [syn: heave, retch]
    v 1: eject the contents of the stomach through the mouth; "After
         drinking too much, the students vomited"; "He purged
         continuously"; "The patient regurgitated the food we gave
         him last night" [syn: vomit, vomit up, purge, cast,
         sick, cat, be sick, disgorge, regorge, retch,
         puke, barf, spew, spue, chuck, upchuck, honk,
         regurgitate, throw up] [ant: keep down]
    2: make an unsuccessful effort to vomit; strain to vomit [syn:
       gag, heave, retch]