in·ter·leave I. \ˌintə(r)ˈlēv\transitive verb (-ed/-ing/-s) Etymology:inter- + -leave (back-formation from leaved, taken as a past participle) 1. a.: to equip (as a manifold business form) with an interleaf b.: slip-sheet 2.: interlaminate, interstratify II. transitive verb : to arrange in or as if in alternate layers