Unaware means not knowing that something is so. Walking on with no idea what has just happened behind you.
It takes of or a clause: unaware of the change, unaware that anybody was watching. The word carries no blame, which is what separates it from ignorant, and that neutrality makes it useful in careful writing. Note the difference from unawares, with an s, which is an adverb and means by surprise — being caught unawares. Aware is the positive form, and awareness is the noun that campaigns are always trying to raise.
1adjectiveunawareNot knowing about something.
“He seemed unaware of the fuss he had caused.”
Proto-Indo-European
*worós — attentive
Proto-West Germanic
*gawar
Old English
ġewær — aware
Middle English
aware,iwar,iware,ywar
English
aware
English, today
unaware
Built from
From un- + aware. aware Middle English aware,iwar,iware,ywar, from Old English ġewær (“aware”), from Proto-West Germanic gawar, from Proto-Germanic waraz (“aware, cautious”), from Proto-Indo-European worós (“attentive”), from wer- (“to heed; watch out”). Cognate with Dutch gewaar, German gewahr, Danish var, Swedish var, Icelandic varr.
Etymology from Wiktionary, CC BY-SA