Semivowel comes from Latin 'semivocalis', a compound of 'semi-' ('half') + 'vocalis' ('vocal, sounding'), from 'vox' ('voice'); a calque carried into English. The historical chain includes Latin semi- and Latin vocalis. The quoted older senses, "semivocalis", "semi-", "half", "vocalis", and "vocal, sounding", supply the semantic anchors for semivowel. The formation is best read as compound and borrowed: the word semivowel carries its older form-history into a compact English lexical shape. In present English it is used as a noun, "a speech sound such as w or y that functions like both vowel and consonant". Related English forms include vowel, semi, and glide. The result is a noun whose etymology preserves both the older form and the later English specialization.