Other forms: pads, padded, padding
A pad is a soft flat thing that cushions, soaks up or protects — and, as a verb, to pad is to walk on quiet feet. Picture a cat padding across the kitchen tiles at night, or your own bare soles crossing a bedroom in the dark.
The noun spreads wide. A writing pad is sheets of paper glued along the top; knee pads and shoulder pads take the knock; a cotton pad lifts off make-up; a launch pad holds a rocket; the pads of your fingers are the soft undersides you press a screen with. To pad also means to stuff something with soft material — a padded envelope, a padded jacket — and from there, to pad out a report with pages nobody needs. The walking sense is quiet and animal: cats, dogs and people in socks pad. Nobody pads in boots.
1nouncushionA soft flat piece of material used to cushion, protect or soak up.
“She taped a pad of gauze over the cut before pulling his sleeve down.”
2nounblockA block of sheets of paper glued along one edge.
“He tore the top sheet off the pad and started the list again.”
3verbfillTo fill or cover something with soft material.
“The envelope was padded so the glass would survive the post.”
4verbpadTo walk with soft, quiet steps.
“He padded downstairs in his socks to check the front door.”
5nounfleshyThe soft fleshy underside of a finger or of an animal's foot.
“The dog left wet prints from its pads across the hall.”
6nounplatformA flat platform built for a particular use, such as landing or launching.
“The helicopter lifted off the pad and turned out to sea.”
7verblongerTo make something longer by adding material that is not needed.
“She had padded the essay with quotations to reach the word count.”
Pad turns up in 1554 meaning a bundle of straw to lie on, and nobody is sure whether all the later pads — the cushion, the paper block, the soft footstep — are really one word. The pad of a finger or a paw has a clearer line: West Flemish pad, the sole of the foot, running back to a Proto-Indo-European root *pent-, to pass. If that line holds, the pads of your feet are cousins of both path and find.
Proto-Indo-European
*pent- — to pass
vls
pad — sole of the foot
English, today
pad
1554, "bundle of straw to lie on". unknown, and unclear all senses have common etymology. For sense "ends of a digit", cf. Low German - or vls pad (“sole of the foot”), perhaps ultimately from Proto-Indo-European pent- (“to pass”), which would make it related to both path and find.
Etymology from Wiktionary, CC BY-SA