o ‧ bliv ‧ i ‧ ous /əˈblɪviəs/ BrE AmE adjective [not before noun]
not knowing about or not noticing something that is happening around you SYN unaware
oblivious of/to
He seemed oblivious to the fact that he had hurt her.
seemingly/apparently oblivious
Congress was seemingly oblivious to these events.
—obliviousness noun [uncountable]