interleaf UK /ˈɪntəliːf/US /ˈɪntɚliːf/noun 2verb 1forms 4 noun2 •A leaf, often of tissue paper or other thin paper, inserted between the pages of a book to protect illustrations. •A sheet of paper or cardboard, placed between layers on a pallet to create a cohesive structure.If you stack high columns of these boxes without using interleafs they'll fall apart. verb1 •Same as interleave formsinterleafed · interleafing · interleafs · interleaves