There are 9 words that start with 'catar'.
| catarrh | cataract | catarrhs | 
| cataracts | catarrhal | catarrhine | 
| cataractous | catarrhally | catarrhines | 
Note: These 9 words that start with 'catar' are found from the USA & Canada version of the tournament Scrabble word list.