Dictionary entry

Decuman

Webster's Dictionary 1913

Dec″u‐man (?), a. [L. decumanus of the tenth, and by metonymy, large, fr. decem ten.] Large; chief; — applied to an extraordinary billow, supposed by some to be every tenth in order. Also used substantively. “Such decuman billows.” Gauden. “The baffled decuman.” Lowell.