subtend

The story

1. Ancient Greek · semantic loan fromὑποτείνω“to subtend”
2. Latin · derived fromsubtendere
3. English todaysubtend

From Latin subtendere, from sub (“under”) + tendere (“to stretch, extend”), itself a semantic loan from Ancient Greek ὑποτείνω (hupoteínō, “to subtend”), from which hypotenuse also derives. See tend.