1550s, "bundle of straw to lie on," possibly from or related to Low German or obsolete Flemish pad "sole of the foot," which is perhaps from PIE *pent- "to tread, go" (see find (v.)), but cf. path (n.). Meaning "cushion-like part of an animal foot" is from 1790 in English. Generalized sense of "something soft" is from c.1700; the sense of "a number of sheets fastened together" (in writing pad, drawing pad, etc.) is from 1865.
Sense of "takeoff or landing place for a helicopter" is from 1960. The word persisted in underworld slang from early 18c. in the sense "sleeping place," and was popularized again c.1959, originally in beatnik speech (later hippie slang) in its original English sense of "place to sleep temporarily."
"to walk," 1550s, probably from Middle Dutch paden "walk along a path, make a path," from pad, pat "path." Originally criminals' slang, perhaps of imitative origin (sound of feet trudging on a dirt road). Related: Padded; padding.
A soft material forming a cushion, used in applying or relieving pressure on a part, or in filling a depression so that dressings can fit snugly.
A fatty mass of tissue acting as a cushion in the body, such as the fleshy underside of a finger or toe.
Taking bribes and graft; on the take
[1970+ Police; fr the pad, a notebook listing the names of corrupt police officers]
To increase the amount or length of: He was padding his expense account (1913+)