The term 'solitary one' can be described by three crossword solutions: EREMITE (7 letters), LONER (5 letters), and RECLUSE (7 letters). An EREMITE is a person who lives in seclusion, typically for religious reasons. A LONER is someone who prefers to be alone and avoids social interaction. A RECLUSE is someone who avoids contact with other people and lives in isolation. All three terms refer to someone who chooses to live alone and away from society.