Origin: 1350–1400; ME < L peregrīnus foreign, deriv. of peregrē abroad, lit., through (i.e., beyond the borders of) the field, equiv. to per-per-+ -egr-, comb. form of ager field + -ē adv. suffix; see -ine1
[Middle English, from Old French, from Medieval Latin peregrīnus, wandering, pilgrim, from Latin, foreigner, from pereger, being abroad : per-, through; see per- + ager, land; see agro- in Indo-European roots.]
"type of falcon," 1555, short for peregrine falcon (c.1386), 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.