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pico (2) m. (Noun) "beak;" "mouth"
14th cent. From Latin beccus 'id.' The change from Latin b- to p- in Spanish was under influence from picar. Borrowed from a Celtic source (compare Gaulish beccus "beak"). From Proto-Celtic *bek(k)o- 'id.' Of unknown origin. Possibly borrowed from a substrate language or of imitative origin.
Asturian picu, Portuguese bico, Galician bico, Catalan bec, French bec, Italian becco
Gizpuzkoan moko "beak," "bill," Zuberoan mosko 'id.,' speculated by Mitxelena (1961) to be an expressive formation of beko "forehead;" possibly loanwords from the same Celtic source (see Trask 2008)