注大乘入楞伽經 6.123

6.123

言妄想習氣為因，喉舌齶等為緣，出諸音聲文字談說，故名為語。

This means that with the habitual tendencies of false conceptualization as cause, and the throat, tongue, palate, and so forth as conditions, uttering various vocal sounds, letters, and conversation is therefore termed words.