Merriam-Webster's Collegiate® Dictionary, 11th Edition
STAPLE
I. noun
Etymology: Middle English stapel post, staple, from Old English stapol post; akin to Middle Dutch stapel step, heap, emporium, Old English steppan to step
Date: 13th century
a usually U-shaped fastener: as, a metal loop both ends of which are driven into a surface to hold the hook, hasp, or bolt of a lock, secure a rope, or fix a wire in place, a small wire both ends of which are driven through layers of thin and easily penetrable material (as paper) and usually clinched to hold the layers together, a usually metal surgical fastener used to hold layers of tissue together (as in the closure of an incision),
II. transitive verb (stapled; stapling)
Date: 14th century
to provide with or secure by staples,
III. noun
Etymology: Middle English, from Anglo-French estaple, from Middle Dutch stapel emporium
Date: 15th century
a town used as a center for the sale or exportation of commodities in bulk, a place of supply ; source , a chief commodity or production of a place,
4. a commodity for which the demand is constant, something having widespread and constant use or appeal, the sustaining or principal element ; substance , raw material ,
6. textile fiber (as wool and rayon) of relatively short length that when spun and twisted forms a yarn rather than a filament, the length of a piece of such textile fiber,
IV. adjective
Date: 1615
used, needed, or enjoyed constantly usually by many individuals, produced regularly or in large quantities , principal , chief