infinitive

The story

1. Latin · derived fromīnfīnītus“unlimited, infinite”
2. Late Latin · derived fromīnfīnītīvus“unlimited, indefinite”
3. Middle English · inherited frominfenitife“without end, in perpetuity”
4. English todayinfinitive

From Middle English infenitife (“without end, in perpetuity”), from Late Latin īnfīnītīvus (“unlimited, indefinite”), from Latin īnfīnītus (“unlimited, infinite”). By surface analysis, infinite + -ive.

Words from the same roots