plies, plying, plied, plied1 [intransitive, transitive] (literary or Indian English) (of ships, buses, etc.) to travel regularly along a particular route or between two particular places+ adverb/preposition Ferries ply across a narrow strait to the island.The train plies twice a day between Paris and Madrid.Buses ply regularly to and from these places.ply something canals plied by gondolas and steam boatsships plying the route between Tripoli and Malta2 [transitive] ply something (formal) to use a tool, especially in a skilful wayThe tailor delicately plied his needle.
ply your trade
to do your work or businessThis is the restaurant where he plied his trade as a cook.Drug dealers openly plied their trade in front of children.
ply for hire/trade/business(British English) to look for customers, passengers, etc. in order to do businesstaxis plying for hire outside the theatre