lonesome

1 ENTRIES FOUND:
lonesome /ˈloʊnsəm/ adjective
lonesome
/ˈloʊnsəm/
adjective
Britannica Dictionary definition of LONESOME
[more lonesome; most lonesome] chiefly US
1 
: sad from being apart from other people : lonely
2 
: causing sad feelings that come from being apart from other people : lonely
3 
: not visited by or traveled on by many people : lonely

(all) by your lonesome

informal
: without anyone else : entirely alone