Usage  the form -ize has been in use in english since the 16th c.; it is widely used in american english, but is not an americanism. The alternative spelling -ise (reflecting a french influence) is in common use, esp. In british english, and is obligatory in certain cases: (a) where it forms part of a larger word-element, such as -mise (= sending) in compromise, and -prise (= taking) in surprise; and (b) in verbs corresponding to nouns with -s- in the stem, such as advertise and televise.