Borrowed from New Latin latex (“clear fluid which is part of a humour or bodily fluid”), a later use of Latin latex (“water; liquid, fluid”). Potentially a borrowing from Ancient Greek λᾰ́τᾰξ (lắtăx, “drop of wine”), reformed by analogy to other nouns in -ex. The semantic shift, however, from drop of wine to water is difficult to explain and may indicate that both words originated from a separate language. Perhaps from the same root as Proto-Celtic *latis (Old Irish laith (“liquid, beer”), Welsh llad (“beer”)) or Proto-Germanic *ladjō- (Old High German letto (“clay, loam”), Old Norse leðja (“mud, dregs”)) or from a Pre-Greek language.