'outro' originates from English, a blend of the word 'out' and the clipped form 'intro' (from 'introduction'), where 'out' meant 'outside/end' and 'intro' meant 'introduction'.

'intro' is a shortening of 'introduction', from Latin 'introductio'/'introducere' via Middle English; 'outro' was formed by analogy to 'intro' in modern English usage (20th century) and became established as the term for an ending segment.

Initially coined by analogy to 'intro' to label an ending segment, its meaning has become the standard term for the concluding part of a program or piece of music.