also pen-knife, "small pocket-knife," early 15c., penne-knif, from pen (n.1) + knife (n.). So called because such small knives were used to make and mend quill pens.
590s, "one who writes a good hand, one skilled in penmanship;" 1610s, "copyist, clerk, scrivener" (obsolete), from pen (n.1) + man (n.).
pasta in the form of tubes cut diagonally, by 1981, from Italian penne (1875), an extended use of the plural of penna, literally "quill," from Latin penna (see pen (n.1)). So called because the oblique cut resembles the writing tip of a quill pen.
also pen pal, "friend or contact with whom a regular correspondence is conducted," 1931, from pen (n.1) + pal (n.). gradually replacing earlier pen-friend (1919).