the only herb that tricks your tongue into feeling cold air that isn't there
means A fragrant herb whose oils give a cooling, fresh sensation — and, by extension, the flavoring and the candies made from it; separately, a place where coins are made or the noun and adjective meaning 'brand-new, pristine condition.'
from The plant-and-flavor 'mint' comes from Old English 'minte,' borrowed from Latin 'mentha,' itself taken from Greek 'minthe' — which in myth was a nymph crushed underfoot and turned into the sweet-smelling herb. The coin-making 'mint' is a completely separate word: it traces to Latin 'moneta,' an epithet of the goddess Juno, near whose temple Roman coins were struck — the same root that gave us 'money.' The two mints only sound alike by accident of history.