shiplap /ˈʃɪp(ˌ)læp/noun 1verb 1forms 3 noun1 •A type of wooden board that has rabbets to allow them to be overlapped, commonly used for the exterior siding of buildings.He stood on the horse and located several long pieces of one-by-eight shiplap and pulled them down. — 1975 verb1 •To overlap boards by this means. formsshiplapped · shiplapping · shiplaps