early 15c., "signify, show, bear or convey in meaning," from Latin importare "bring in, convey, bring in from abroad," from assimilated form of in- "into, in" (from PIE root *en "in") + portare "to carry," from PIE root *per- (2) "to lead, pass over." In English, the sense of "bring from another state or land," especially "bring in goods from abroad" is recorded by 1540s. As "be important" from 1580s. Related: Imported; importing.
-ation
the end of some nouns of action; see -ate + -ion.
non-importation n.
also nonimportation, "a refraining from importing," 1770, from non- + importation.