The Collaborative International Dictionary of English v.0.48:

Entomb \En*tomb"\, v. t. [imp. & p. p. Entombed; p. pr. & vb.
   n. Entombing.] [Pref. en- + tomb: cf. OF. entomber.]
   To deposit in a tomb, as a dead body; to bury; to inter; to
   inhume. --Hooker.
   [1913 Webster]