Definition from Wiktionary, the free dictionary
solitaire (plural solitaires)
- A person who lives alone; a recluse or hermit.
- (Can we find and add a quotation of Alexander Pope to this entry?)
- Any of various card games that can be played by one person.
- A game for one person, played on a board with pegs or balls, in which the object is, beginning with all the places filled except one, to remove all but one of the pieces by "jumping", as in draughts.
- An extinct bird related to dodo, Pezophaps solitaria, Rodrigues solitaire, that lived on the island of Rodrigues.
- An extinct bird formerly believed to be related to the dodo, more precisely Réunion solitaire, Raphus solitarius, now preferably Réunion ibis, Threskiornis solitarius.
- One of several American species of bird in the genus Myadestes in the thrush family.
- A gem set on its own.
- (loner): hermit
person who lives alone — see solitary
game that can be played by one person
- living or being alone; solitary
living alone or being alone; solitary
Related terms 
- Oxford English Dictionary
From Latin sōlitārius.
solitaire (masculine and feminine, plural solitaires)