Source : Webster's Revised Unabridged Dictionary (1913)

Beefy \Beef"y\, a.
   Having much beef; of the nature of beef; resembling beef;
   fleshy.

Source : WordNet®

beefy
     adj : muscular and heavily built; "a beefy wrestler"; "had a tall
           burly frame"; "clothing sizes for husky boys"; "a
           strapping boy of eighteen"; "`buirdly' is a Scottish
           term" [syn: {burly}, {husky}, {strapping}, {buirdly}]
     [also: {beefiest}, {beefier}]