• make or become blue

• wash (white clothes) with bluing

• of a colour intermediate between green and violet, as of the sky or sea on a sunny day

Synonyms: sky blue, azure, cobalt (blue), sapphire, cerulean, navy (blue), saxe (blue), Oxford blue, Cambridge blue, ultramarine, lapis lazuli, indigo, aquamarine, turquoise, teal (blue), cyan, of the colour of the sky, of the colour of the sea

• (of a person or mood) melancholy, sad, or depressed

Synonyms: depressed, down, sad, saddened, unhappy, melancholy, miserable, sorrowful, gloomy, dejected, downhearted, disheartened, despondent, dispirited, low, in low spirits, low-spirited, heavy-hearted, glum, morose, dismal, downcast, cast down, tearful

• (of a film, joke, or story) having sexual or pornographic content

Synonyms: sexually explicit, explicit, indecent, dirty, filthy, obscene, rude, coarse, vulgar, bawdy, lewd, racy, risqué, salacious, naughty, wicked, improper, unseemly, smutty, spicy, raw, off colour, ribald, Rabelaisian

• politically conservative

• blue colour or pigment

• a small butterfly, the male of which is predominantly blue while the female is typically brown

• a person who has represented Cambridge University (a Cambridge blue) or Oxford University (an Oxford blue) at a particular sport in a match between the two universities

• an argument or fight

• a mistake

• a nickname for a red-headed person

• a supporter of the Conservative Party

• squander or recklessly spend (money)

• melancholic music of black American folk origin, typically in a twelve-bar sequence. It developed in the rural southern US towards the end of the 19th century, finding a wider audience in the 1940s, as black people migrated to the cities. This urban blues gave rise to rhythm and blues and rock and roll

• feelings of melancholy, sadness, or depression

Synonyms: depression, sadness, unhappiness, melancholy, misery, sorrow, gloominess, gloom, dejection, downheartedness, despondency, dispiritedness, low spirits, heavy-heartedness, glumness, moroseness, dismalness, despair