Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. missor, ōris, m. [mitto], one who sends, throws, or shoots, an archer (very rare): hic missore vacans fulgens jacet una sagitta (al.: hic misso revocans), Cic. Arat. 84.
2. Missor, a Roman surname, Inscr. Fabr. 365, 111.