There are 15 words that start with 'opu'.
| opus | opuses | opulent |
| opuntia | opulence | opulency |
| opuntias | opuscula | opuscule |
| opulences | opulently | opuscular |
| opuscules | opusculum | opulencies |
Note: These 15 words that start with 'opu' are found from the USA & Canada version of the tournament Scrabble word list.