oblivious

The story

1. Latin · derived fromoblīviōsus“forgetful, oblivious”
2. Middle English · inherited fromoblivious
3. English todayoblivious

From Middle English oblivious, from Latin oblīviōsus (“forgetful, oblivious”), formed from oblīvium (“forgetfulness, oblivion”) + -ōsus (“full of, overly, prone to”), from oblīvīscor (“to forget”).