I. ˈpi-gē-ˌbak adverb
also pick·a·back ˈpi-gē-, ˈpi-kə-
Etymology: alteration of earlier a pick pack, of unknown origin
Date: 1565
1. : up on the back and shoulders
2. : on or as if on the back of another ; especially : on a railroad flatcar
II. noun
also pickaback
Date: circa 1590
1. : the act of carrying piggyback
2. : the movement of loaded truck trailers on railroad flatcars
III. adjective
also pickaback
Date: 1823
1. : marked by being up on the shoulders and back
a child needs hugging, tussling, and piggyback rides — Benjamin Spock
2. : carried or transported piggyback: as
a. : of or relating to the hauling of truck trailers on railroad flatcars
b. : being or relating to something carried into space as an extra load by a vehicle (as a spacecraft)
IV. verb
also pickaback
Date: 1952
transitive verb
1. : to carry up on the shoulders and back
2. : to haul (as a truck trailer) by railroad car
3. : to set up or cause to function in conjunction with something larger, more important, or already in existence or operation
intransitive verb
: to function or be carried on or as if on the back of another