say it: in-ak-TIV-i-tee
inactivity is a noun meaning "the state of being inactive". It carries 3 recorded senses.
a disposition to remain inactive or inert
“he had to overcome his inertia and get back to work”
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 inactivity 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.