The Collaborative International Dictionary of English v.0.48:

Machaerodus \Ma*chae"ro*dus\ (m[.a]*k[=e]"r[-o]*d[u^]s),
Machairodus \Ma*chai"ro*dus\ (m[.a]*k[imac]"r[-o]*d[u^]s), n.
   [NL., fr. Gr. ma`chaira dagger + 'odoy`s tooth.] (Paleon.)
   A genus of extinct mammals allied to the cats, and having in
   the upper jaw canine teeth of remarkable size and strength;
   -- hence called saber-toothed tigers.
   [1913 Webster]