alone

without anybody else or anything else

“the child stayed home alone”

without any others being included or involved

“the burden of proof rests on the prosecution alone”

lacking companions or companionship

“he was alone when we met him”

exclusive of anyone or anything else

“she alone believed him”

radically distinctive and without equal

“he is alone in the field of microbiology”

isolated from others

“could be alone in a crowded room”