thumbs down noun 2thumbs-down verb 1forms 4 noun2 •A gesture signifying disapproval; a thumb pointing down out of a fist.He shook his head and gave a thumbs down. •(figurative) A rejection or refusal.We requested permission but got a thumbs down. thumbs-down verb1 •To disapprove with a thumbs-down sign.He stood outside the dressing room and thumbs-upped or thumbs-downed each choice. — 2015 formsthumbs-downed · thumbs-downing · thumbs-downs · thumbs downs