vapid (adj) – lifeless, dull, or bland; uninspiring
BREAKDOWN: VAP- (steam or mist) + -ID (that which is)
— vapidity and vapidness both describe the lack of liveliness, flavor, taste, or force
This word is built on the root VAP-, which means steam or mist.
Common VAP- words include evaporation and vapor.
More esoteric VAP- words include devaporation and pervaporate.