- blue1 [ blu ] adjective ***1. ) something that is blue is the same color as the sky on a clear sunny day. If something is similar to this color, you can say that it is a bluish color:He looked at her with his pale blue eyes.The sky was gloriously blue.blue with cold: My fingers were turning blue with cold.2. ) INFORMAL feeling slightly sad:She usually calls her mother when she's feeling blue.3. ) INFORMAL OLD-FASHIONED dealing with sex in a way that some people find offensive=> BLUE MOVIEonce in a blue moon INFORMALvery rarely:They come to visit once in a blue moon.scream blue murder BRITISH INFORMALto shout or protest very loudly because you are very angry or feeling a lot of paintalk a blue streak AMERICAN INFORMALto talk a lot without pausinguntil/till you are blue in the face INFORMALused for saying that there is no use in trying to persuade someone to do something because you will not succeed:You can tell your kids not to do something until you're blue in the face, but if they want to do it, they will.╾ blue|ness noun uncountblueblue 2 [ blu ] noun count or uncount **the color of the sky on a clear sunny day:The boy was dressed all in blue.The room had been painted in bright blues and yellows.the boys in blue INFORMALthe policeout of the bluehappening in a way that is sudden and unexpected, and does not seem connected with anything that happened before:Out of the blue she said, Your name's John, isn't it?=> BOLT1
Usage of the words and phrases in modern English. 2013.