[1925–30; aviat(or) + -trix]This word is first recorded in the period 1925–30. Other words that entered Englishat around the same time include: chain reaction, distinctive feature, gimmick, reflex camera, runout-trix is a suffix occurring in loanwords from Latin, where it formed feminine nouns oradjectives corresponding to agent nouns ending in -tor (Bellatrix). On this model, -trix is used in English to form feminine nouns (aviatrix; executrix) and geometrical terms denoting straight lines (directrix)