cool one's heels is a verb meaning "wait or pass the time aimlessly or futilely; be kept waiting". It carries one recorded sense.
wait or pass the time aimlessly or futilely; be kept waiting
“She kicked her heels for hours at the gate of the Embassy”
Definitions, synonyms and semantic relations for cool one's heels come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.