"horse with a light brown or cream coat and a pale mane and tail," 1899, (earlier palomino horse), from American Spanish palomino "cream-colored horse," from Spanish, literally "young dove," perhaps from Italian palombino "dove-colored," from Latin palumbinus "of wood pigeons," from palumba "wood pigeon" (from PIE root *pel- (1) "pale"). The type of horse was so called because of its dove-like coloring.
by 1926, "mediocre prizefighter," of unknown origin, credited to U.S. sportswriter and Variety magazine staffer Jack "Con" Conway (1898-1928), who might at least have popularized it. Non-boxing sense of "average person" is from Joe Palooka, hero of Ham Fisher's boxing-themed comic strip, which debuted in 1930.
"feeler, tactile organ," 1836, from French palpe, German palp, from Latin palpus "feeler," related to palpare "to touch softly, feel," which is of uncertain origin (see palpable).
late 14c., "that can be felt, perceptible by the touch," from Late Latin palpabilis "that may be touched or felt," from Latin palpare "touch gently, stroke," a word de Vaan finds to be of no known etymology (rejecting the connection in Watkins, etc., to a reduplication of the PIE root *pal-, as in feel (v.), on phonetic grounds). Some sources suggest it is onomatopoeic. The figurative sense of "easily perceived, evident, clear, obvious" also is from late 14c., on the notion of "seeming as if it might be touched." Related: Palpably; palpability.
"act of touching, feeling by the sense of touch," late 15c. (Caxton), from French palpation, from Latin palpationem (nominative palpatio) "a stroking; flattering, flattery," noun of action from past-participle stem of palpare "to touch" (see palpable). Used in English in literal sense.
"of or pertaining to the eyelids," by 1756, from Late Latin palpebralis, from Latin palpebra "the eyelids," which is probably from palpare "to stroke" (see palpable), perhaps via an unrecorded verb *palpere "to move repeatedly."