There are 16 words that end with 'niac'.
| maniac | ammoniac | brainiac |
| demoniac | simoniac | egomaniac |
| insomniac | monomaniac | pyromaniac |
| algolagniac | dipsomaniac | mythomaniac |
| bibliomaniac | megalomaniac | kleptomaniac |
| nymphomaniac | ||
Note: These 16 words that end with 'niac' are found from the USA & Canada version of the tournament Scrabble word list.