From Longman Dictionary of Contemporary Englishheavy-dutyˌheavy-ˈduty adjective 1 VERYheavy-duty materials are strong and thick and not easily damaged heavy-duty canvas► see thesaurus at strong2 TMACHINEheavy-duty machines or equipment are designed to be used for very hard work3 especially American English informalSERIOUS/NOT JOKING very complicated, serious, or extreme Today, she was going to do some heavy-duty cleaning.
Examples from the Corpus
heavy-duty• The bathroom needs a heavy-duty cleaning job.• a heavy-duty conversation• The emergency equipment includes food, a first-aid kit, and a heavy-duty flashlight.• You unpack the orb from the heavy-duty insula-tion stuffed around it.• heavy-duty plastic garbage bags• The principal technical problems which had to be resolved were breakage due to heavy-duty service and abuse.• Use a heavy-duty solvent-based type instead if the roof surface is in very poor condition.• She turned on his heavy-duty torch.• If you are going to put an electric cable underground, you must use the special heavy-duty type.• This began the race to find the perfect pump designed for heavy-duty use in rural communities of developing countries.From Longman Business Dictionaryheavy dutyˌheavy ˈduty (also heavy-duty) adjective [only before a noun] heavy duty materials, equipment etc are strong and suitable for hard workheavy-duty gearboxes used in tanksheavy duty workwear → compare light-duty, medium-duty 