ply
verb uk/plaɪ/ us/plaɪ/
(WORK)
[ T ]经常从事（尤指卖东西的活儿）；兜售
to sell or to work regularly at something, especially at a job that involves selling things
Fishermen in small boats ply their trade up and down the coast. 渔民们驾着小船沿着海岸兜售海鲜。
Dealers are openly plying drugs in school playgrounds. 毒品贩子公然在校园操场上兜售毒品。
The market traders were loudly plying their wares. 市场上的商贩们在高声叫卖他们的商品。
ply for business, trade, etc. mainly UK 招徕顾客；等生意
to try to get customers for your business in a public place, for example, as a taxi driver, by driving around or waiting in a regular place
There are never any taxis plying for trade/hire in our area. 我们这一地区从来都没有出租车在这里候客。
I noticed a couple of prostitutes plying for business on the corner. 我看到拐角处有几个妓女在拉客。
The music was drowned out by the shouts of traders plying for business.
The first ice cream shop was so successful that there were soon many other such establishments plying for trade.
The vehicle was not licensed to ply for hire.
(TRAVEL)
[ I + adv/prep, T ] old-fashioned定期往返（于）
When a boat, train, bus, etc. plies a particular route, it makes that journey regularly.
High-speed trains regularly ply between Paris and Lyons. 高速列车定期往返于巴黎和里昂之间。
This airline has been plying the transatlantic route for many years. 这家航空公司经营跨大西洋航线已经很多年了。
Phrasal verb
ply someone with something 持续向（某人）提供（通常指食物、饮料）
to keep giving a person something, usually food or drink
John's been plying me with drinks all evening. 约翰整个晚上都在给我斟酒。
拿（工作、表格或问题）纠缠（某人）;不停地让（某人）回答（问题）
to keep giving someone work or forms to complete, or asking them questions
We plied Charlie with questions about his trip round the world. 我们不停地问查利他周游世界的事情。
ply
noun [ U ] uk/plaɪ/ us/plaɪ/
（线等的）层，股
the particular number of threads from which wool, rope, etc. is made, used as a measure of its thickness
six balls of four-ply (wool) 6个有4股毛线的线球
What ply do you need for that knitting pattern? 那个编结样式需要用几股毛线？
（胶合板或纸巾的）层
the particular number of layers from which plywood or tissue is formed, used as a measure of its thickness
Will three-ply (= woolmade from three layers stuck together) be strong enough for making a shelf? 三层夹板搭的架子是否够结实？