blue

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours. (countable, uncountable)
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour. (countable, uncountable) · I don't like red Smarties. Have you got a blue?
3. A blue dye or pigment. (countable, uncountable)
4. Blue clothing. (uncountable) · The boys in blue marched to the pipers.
5. A blue uniform. See blues. (countable, uncountable)
6. A member of a sports team that wears blue colours; (in the plural) a nickname for the team as a whole. See also blues. (countable, uncountable) · Come on, you blues!
7. An umpire, in reference to the typical dark-blue colour of the umpire's uniform. Sometimes perceived by umpires as derogatory when used by players or coaches while disputing a call. (countable, slang, uncountable) · He was safe! Terrible call, blue!
8. Sporting colours awarded by a university or other institution for sporting achievement, such as representing one's university, especially and originally at Oxford and Cambridge Universities in England. See also full blue, half blue. (countable, uncountable) · He excelled at rowing and received a blue in the sport at Oxford.

Plural blues