:: COMPARE ::
The short answer
A compound joins two whole words; a portmanteau fuses them and loses material in the process. 'Bookshop' keeps both. 'Brunch' keeps neither — and the missing letters are what makes it one word rather than two.
Side by side
| Aspect | Portmanteau | Compound |
|---|---|---|
| Words survive intact | No | Yes |
| Material lost | Yes | No |
| Example | smog | bookshop |
| Linguists' term | Blend | Compound |
What each one means
A word made by fusing two others so their meanings pack together — brunch, smog, motel, podcast. The name is literal: a portmanteau is a travelling case that opens into two equal halves, which is why Lewis Carroll reached for it when he had Humpty Dumpty explain that two meanings were 'packed up into one word'.
Full definition of Portmanteau →The contrast above sets out how Compound differs from Portmanteau on the points that actually matter.