Is it ensure, insure, or assure?
1580s, "resolution of anything complex into simple elements" (opposite of synthesis), from Medieval Latin analysis (15c.), from Greek analysis "a breaking up, a loosening, releasing," noun of action from analyein "unloose, release, set free; to loose a ship from its moorings," in Aristotle, "to analyze," from ana "up, throughout" (see ana-) + lysis "a loosening," from lyein "to unfasten" (see lose). Psychological sense is from 1890. Phrase in the final (or last) analysis (1844), translates French en dernière analyse.
chiefly British English spelling of analyze (q.v.).
Analyse is better than analyze, but merely as being the one of the two equally indefensible forms that has won. The correct but now impossible form would be analysize (or analysise), with analysist for existing analyst. [Fowler]
analysis a·nal·y·sis (ə-nāl'ĭ-sĭs)
n. pl. a·nal·y·ses (-sēz')
The separation of a whole into its constituent parts for individual study.
The separation of a substance into its constituent elements to determine either their nature or proportions.
The stated findings of such a separation or determination.