Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
complementarity is a noun meaning "a relation between two opposite states or principles that together exhaust the possibilities". It carries 2 recorded senses.
a relation between two opposite states or principles that together exhaust the possibilities
the interrelation of reciprocity whereby one thing supplements or depends on the other
“the complementarity of the sexes”
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 complementarity come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.