alone in WordNet English dictionary

1. without any others being included or involved
   "was entirely to blame"; "a school devoted entirely to the needs of problem children"; "he works for Mr. Smith exclusively"; "did it solely for money"; "the burden of proof rests on the prosecution alone"; "a privilege granted only to him"
   entirely  exclusively  solely  alone  only  entirely  exclusively  solely  alone  only 
   
2. without anybody else or anything else
   "the child stayed home alone"; "the pillar stood alone, supporting nothing"; "he flew solo"
   alone  solo  unaccompanied  alone  solo  unaccompanied 
   

1. exclusive of anyone or anything else
   "she alone believed him"; "cannot live by bread alone"; "I'll have this car and this car only"
   alone  only 
   
2. radically distinctive and without equal
   "he is alone in the field of microbiology"; "this theory is altogether alone in its penetration of the problem"; "Bach was unique in his handling of counterpoint"; "craftsmen whose skill is unequaled"; "unparalleled athletic ability"; "a breakdown of law unparalleled in our history"
   alone  unique  unequaled  unequalled  unparalleled 
   
3. lacking companions or companionship
   "he was alone when we met him"; "she is alone much of the time"; "the lone skier on the mountain"; "a lonely fisherman stood on a tuft of gravel"; "a lonely soul"; "a solitary traveler"
   alone  lone  lonely  solitary 
   
4. isolated from others
   "could be alone in a crowded room"; "was alone with her thoughts"; "I want to be alone"
   alone