- The definition of humid is there is a lot of water vapor in the air.
When the air feels wet, heavy and sticky, this is an example of when it is humid.
Origin of humidFrench humide ; from Classical Latin humidus ; from humere, altered (after humus) ; from umere, to be moist: see humor
Origin of humidMiddle English, from Latin hūmidus, from hūmēre, to be moist.
(comparative more humid, superlative most humid)
From Old French humide, from Latin humidus, correctly umidus (“moist”), from humere, correctly umere (“to be moist”), akin to ūvēns (“moist”), ūvidus, ūdus (“moist”); all from Proto-Indo-European *wegʷ-, *wogʷ- (“wet”). Cognate with Old Norse vǫkr (“moist, damp, wet”), Scots wak (“moist, damp, wetness, moisture”), English weaky (“moist, wet”). More at weaky.