singleton

One that is single, especially.

A child or animal born as a single birth, especially in contrast to one that is part of a multiple birth.

A playing card that is the only one of its suit in a player’s hand.

An unmarried person.

A nongeminate consonant.

An individual separated or distinguished from two or more of its group.

A silly fellow; a simpleton.

In whist, a hand containing only one card of some suit; a card which is the only one of a suit in the hand of a player.

In certain games at cards, as whist, a single card of any suit held at the deal by a player.

A playing card that is the only one of its suit in a hand, especially at bridge.