Katakana, a set of Japanese syllabary characters, secondary to hiragana, derived from portions of Chinese characters whose sounds approximate the Japanese sound being represented. Chiefly thought of as being used for loanwords (cf. カタカナ語 (“loanword”, literally “katakana word”)), it has a number of other uses too, complementing hiragana; see Katakana#Usage on Wikipedia.Wikipedia

a mixed script of kanji and katakana, or a use of such script, that was common in formal writing, before modern orthographic reforms which favored hiragana over katakana for grammatical elements such as particles and inflectional affixes