Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
complementation is a noun meaning "the grammatical relation of a word or phrase to a predicate". It carries 2 recorded senses.
the grammatical relation of a word or phrase to a predicate
(linguistics) a distribution of related speech sounds or forms in such a way that they only appear in different contexts
linguistics
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 complementation come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.