lubricate
/ˈlu:brɪkeɪt; `lubrɪˌket/ v[Tn]
put oil or grease on or in (machinery, etc) so that it moves easily 给（机械等）加润滑油
lubricate the wheels, bearings, hinges, etc 给轮子、 轴承、 合叶等加润滑油
(fig 比喻) My throat needs lubricating, ie with a drink. 我需要润润嗓子了.