The phrase "gave thumbs-up" expresses approval or agreement. Antonyms for this phrase would be words or phrases that express the opposite sentiment - disapproval or disagreement. Some common antonyms for "gave thumbs-up" include "disapproved", "opposed", "rejected", "vetoed", "condemned", "criticized", "objected", "refused", "denied". Depending on the context and tone, other antonyms may include "blocked", "obstructed", "hindered", "thwarted", "interfered with", "stymied". Using antonyms for "gave thumbs-up" can help to communicate a different meaning, and may be useful in debates, discussions, or critiques.