Left a person solitary (4)
I believe the answer is:
lone
'solitary' is the definition.
(synonyms)
'left a person' is the wordplay.
'left' becomes 'l' (common abbreviation).
'a person' becomes 'one'.
'l'+'one'='LONE'
(Other definitions for lone that I've seen before include "Single and isolated" , "He likes to operate by himself" , "The ... Ranger, fictional masked cowboy" , "Solitary, without companions" , "Companionless" .)