1350-1400;Middle English < Latinperegrīnus foreign, derivative of peregrē abroad, literally, through (i.e., beyond the borders of) the field, equivalent to per-per- + -egr-, combining form of ager field + -ē adv. suffix; see -ine1
"type of falcon," 1555, short for peregrine falcon (late 14c.), from O.Fr. faulcon pelerin (c.1263), from M.L. falco peregrinus (see peregrination). Sense may have been a bird "caught in transit," as opposed to one taken from the nest.