/ hjuːˈmɪdəti; NAmE / noun [ U ]
1.
the amount of water in the air :
high / low humidity
70% humidity
2.
conditions in which the air is very warm and damp :
These plants need heat and humidity to grow well.
The humidity was becoming unbearable.
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WORD ORIGIN
late Middle English : from Old French humidite or Latin humiditas , from humidus , from humere be moist.