Definition of missionarize in English:

missionarize

(also missionarise)

Pronunciation /ˈmɪʃ(ə)nərʌɪz/ /ˈmɪʃ(ə)nrʌɪz/

verb

rare
  • no object To do missionary work.

Origin

Mid 19th century (in an earlier sense). From missionary + -ize.