Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
self-sacrifice is a noun meaning "acting with less concern for yourself than for the success of the joint activity". It carries one recorded sense.
acting with less concern for yourself than for the success of the joint activity
Definitions, synonyms and semantic relations for self-sacrifice come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.