word-forming element used in making names for very small units of measure, 1915 (formally adopted as a scientific prefix meaning "one trillionth" by the International System of Units, 1960), from Spanish pico "a little over, a small balance," literally "sharp point, beak," a word of Celtic origin (compare Gaulish beccus "beak").
Entries linking to pico-
picosecond n.
unit of time equal to one trillionth of a second, 1966, from pico- + second (n.).