Polyurethane is a kind of plastic. The sense you need here is the one in a paint shop: people use it to make paints and varnish — the tough, often shiny coat that goes on wood, floors, and sometimes cars or boats.

Polyurethane is a kind of plastic是一種塑膠。The sense you need here你這裡需要知道的意思 is the one in a paint shop是油漆行裡說的那個意思 people use it to make paints and varnish大家用它來做油漆和亮光漆 — the tough, often shiny coat也就是那種堅固、常常有光澤的塗層 that goes on wood, floors, and sometimes cars or boats塗在木頭、地板，有時候也塗在車子或船上。

It dries into a hard skin that water and scratches do not get through easily. Though actually the same family of plastic turns up in a lot of other places too (soft foam, some fake-leather bags), a tin labelled polyurethane, or PU, is usually this coating.

It dries into a hard skin乾了以後會變成一層硬皮 that water and scratches do not get through easily水和刮傷都不容易穿透。Though actually不過其實 the same family of plastic turns up in a lot of other places too同一個塑膠家族也出現在很多其他地方（soft foam, some fake-leather bags）（像軟泡棉、一些仿皮包） a tin labelled polyurethane, or PU, is usually this coating但一罐標示polyurethane或PU的東西，通常就是指這種塗料。

It is a technical word. In ordinary talk people just say the varnish, the clear coat, or PU paint.

It is a technical word是個技術性的字。In ordinary talk日常說話裡 people just say the varnish, the clear coat, or PU paint大家就直接說the varnish、the clear coat，或PU paint。

You almost never need it as a verb in school English, though a factory may say they polyurethane a floor, meaning they paint this stuff on.

You almost never need it as a verb in school English在學校英文裡你幾乎用不到它當動詞 though a factory may say they polyurethane a floor不過工廠可能會說他們polyurethane一片地板 meaning they paint this stuff on意思是把這種塗料塗上去。