tails
n. uncountable B1 Intermediate US //ˈteɪɫz// UK //tˈeɪlz// tails
n. the side of a coin that does not have a picture of a person's head on it. You use this word when you flip a coin to make a decision.
n. the reverse side of a coin, opposite the side bearing a portrait or principal design. Frequently used in the plural form when referring to the outcome of a coin toss.
I chose tails, but the coin landed on heads.
We decided who would go first by flipping a coin; it came up tails, so Sarah started.
The probability of a fair coin landing on tails remains exactly fifty percent, regardless of how many times heads has appeared in previous tosses.
Usage
Usually treated as uncountable when referring to the side of a coin in the game 'heads or tails'.