say it: ER-luhs
airless is an adjective meaning "lacking fresh air". It carries one recorded sense.
lacking fresh air
“a dusty airless attic”
“the dreadfully close atmosphere”
“hot and stuffy and the air was blue with smoke”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for airless come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.