There are 7 15-letter words that start with 'mer'.
| mercaptopurines | mercenarinesses |
| merchantability | mercilessnesses |
| mercurialnesses | meritoriousness |
| meroblastically | |
Note: These 7 15-letter words that start with 'mer' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with merc, meri, merr, merg, mero, merl, mere, merm, merb, merd, merk.
4-letter words start with 'mer' (4)