Not aware of or not noticing something that is happening around you.
From Latin 'obliviosus' meaning forgetful, derived from 'oblivio' (forgetting), which comes from 'obliviscus' (to forget). The word evolved in English to mean not just forgetting, but being unaware.
Psychologists have found that being oblivious is connected to 'inattentional blindness'—your brain literally doesn't process information it's not focused on, which is why you can be genuinely unaware of something right in front of you; it's not stupidity, it's how attention works!
Complete word intelligence in one call. Free tier — 50 lookups/day.