A "clarinettist" is someone who plays the clarinet. If you are looking for synonyms for this word, you may use "clarinet player" or "clarinetist." Other options include "woodwind musician" or "reed instrumentalist." Additionally, you might use "woodwind player" or "wind player" depending on the context. A further alternative could be "saxophonist," as the saxophone has a similar sound to the clarinet. Ultimately, the synonym you choose will depend on the overall tone and meaning of the sentence you are writing, as well as the specific musical genre or setting in which the musician is performing.