from
The Collaborative International Dictionary of English v.0.48
Rare \Rare\, a. [Compar. {Rarer} (r[^a]r"[~e]r); superl.
{Rarest}.] [Cf. AS. hr[=e]r, or E. rare early. [root]18.]
Nearly raw; partially cooked; not thoroughly cooked;
underdone; as, rare beef or mutton.
[1913 Webster]
New-laid eggs, which Baucis' busy care
Turned by a gentle fire, and roasted rare. --Dryden.
[1913 Webster]
Note: This word is in common use in the United States, but in
England its synonym {underdone} is preferred.
[1913 Webster]