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atonicity

American  
[at-n-is-i-tee, ey-toh-nis-] / ˌæt nˈɪs ɪ ti, ˌeɪ toʊˈnɪs- /

noun

Pathology.
  1. lack of tone; atony.


Etymology

Origin of atonicity

First recorded in 1895–1900; atonic + -ity