Hebrew שַׁעַטְנֵז, which refers to a mixed fabric, occurs only in Lev 19:19 and Deut 22:11 in prohibitions of various mixtures. Its meaning is clear, but its etymology has hitherto eluded a convincing explanation. I propose that, as a word denoting a hybrid of materials, שַׁעַטְנֵז is a lexical blend. Its two source words are שַׁאַת* and עִנְז*, the early Hebrew forms of the Semitic words for “ewe” (*ṯaʾat) and “goat” (*ʿanz/*ʿinz), respectively. The resulting blend originally referred to a mixture of sheep and goat wool but was subsequently generalized to designate any mixed fabric, which is precisely what שַׁעַטְנֵז means in Lev 19:19 and Deut 22:11.