Thesaurus.com
Dictionary.com
Definitions

beefy

[bee-fee] / ˈbi fi /
ADJECTIVE
brawny
Synonyms
STRONGEST
burly hulking muscular
WEAK
bulky heavy husky sturdy substantial thickset weighty
Antonyms
WEAK
frail skinny slight slim thin tiny weak

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.