1540s, "to spend time with unimportant matters, to work in a trifling way," a word of uncertain origin, apparently a frequentative form. Meaning "to pick at one's food" is from 1610s; that of "urinate" is from 1796 as a childish word. Related: Piddled; piddler; piddling.
picture
picturephone
pictures
picturesque
Picus
piddle
piddling
pidgin
PIE
pie
piebald