somorgujo.

From a derivative of Latin mergus, with various theories existing on the intermediate form: one derives it from the variant form somorgujón, from a Vulgar Latin *merguliōnem, later influenced by Latin submergō (compare Portuguese mergulho, mergulhão, Galician mergullón, somorgullo, Leonese mergollón). Another etymology often considered is deverbal from somorgujar, from a hypothetical Vulgar Latin *submerguc(u)lāre, although this is unlikely for several reasons, one being that the verb was never used as much as this noun. Also possibly is a derivative of Latin mergulus through a verb *merguliāre (compare Portuguese megulhar), with later influence from submergō. Compare also Italian marangone, smergo.