There are 15 11-letter words that start with 'cos'.
| coscripting | cosignatory | cosmetician |
| cosmeticize | cosmetology | cosmogonies |
| cosmogonist | cosmography | cosmolining |
| cosmologies | cosmologist | cosmopolite |
| cosponsored | costiveness | costumeries |
Note: These 15 11-letter words that start with 'cos' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with cosm, cost, cosi, cose, cosh, coss, cosp, cosc, cosu, cosy.
4-letter words start with 'cos' (4)