Antonyms of adj big-chested

1 sense of big-chested

Sense 1
big-chested, chesty -- (marked by a large or well-developed chest; "he was big-chested, big-shouldered and heavy-armed")

INDIRECT (VIA robust) -> frail -- (physically weak; "an invalid's frail body")

Similarity of adj big-chested

1 sense of big-chested

Sense 1
big-chested, chesty -- (marked by a large or well-developed chest; "he was big-chested, big-shouldered and heavy-armed")
       => robust (vs. frail) -- (sturdy and strong in form, constitution, or construction; "a robust body"; "a robust perennial")