heavy-duty adjective 2heavy duty noun 1forms 2 adjective2 •Designed to withstand hard usage without breaking; hard-wearing.The cars are constructed to the normal B.R. standard coach specifications and mounted on heavy-duty B.R.2 type bogies with B.T.R. rubber vibro-insulators on the bearing springs. — 1960 •(informal) Very serious, intense, or demanding.Summit still has to ... summit some final steps before it can start crunching heavy-duty science. — 2017 heavy duty noun[before a noun]1 •Strenuous service. formsheavier-duty · heaviest-duty
