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Old English æl "awl, piercer," from Proto-Germanic *ælo (cf. Old Norse alr, Dutch aal, Middle Low German al, Old High German äla, German Ahle), of uncertain origin. Earliest references are to piercing of the ears, though later it was associated with shoemakers. Through misdivision, frequently written 15c.-17c. as nawl (for an awl; see N).
an instrument only referred to in connection with the custom of boring the ear of a slave (Ex. 21:6; Deut. 15:17), in token of his volunteering perpetual service when he might be free. (Comp. Ps. 40:6; Isa. 50:5).