"fasten," Old English clyppan "to embrace," related to Old Frisian kleppa "to embrace, love," Old High German klaftra, German klafter "fathom" (on notion of outstretched arms), from PIE *glebh- "to roll into a ball" (see glebe). Related: Clipped; clipping. Original sense of the verb is preserved in U.S. football clipping penalty.
"something for attaching or holding," mid-14c., from clip (v.2). Meaning "receptacle containing several cartridges for a repeating firearm" is from 1901. Meaning "piece of jewelry fastened by a clip" is from 1937. This is also the source of paper clip.