From Longman Dictionary of Contemporary Englishpadlockpad‧lock /ˈpædlɒk $ -lɑːk/ noun [countable] 
TDa lock that you can put on a gate, door, bicycle etc He undid the padlock and eased back the lid. —padlock verb [transitive]
TDa lock that you can put on a gate, door, bicycle etc He undid the padlock and eased back the lid. —padlock verb [transitive]Examples from the Corpus
padlock• The creak and click of door and padlock roused Midnight.• Ahead stood an unpainted shed with one high window and one door clamped shut with a great padlock.• At this hour they were all barricaded and fortified, protected by wire and armed with heavy padlocks.• Put any valuables out of sight, preferably in a strong locker with a secure padlock.• The dean of students ordered the police to come and cut the padlock, but then to leave the campus.• The padlocks on the gates will also be removed to allow pedestrian access.Origin padlock (1400-1500) pad (of unknown origin) + lock 