Said or written to a deceased person on his or her birthday in order to convey the good wishes of the speaker or writer.

A birthday of a person after his or her death.

(probability theory) The counterintuitive observation that a random group of people needs to have only 23 members before there is a 50% chance of two of them having the same birthday.

Used other than figuratively or idiomatically: see canary, bird. / (slang) A jailbird. / (slang) A mistress.

plural of biradicaloid

plural of birch tree

plural of bird-nest

plural of birth cert

plural of birthday suiter

The storm petrel. / (Australia) The channel-billed cuckoo.