If one thing or person lags behind another thing or person, their progress is slower than that of the other.
例句
Britain still lags behind most of Europe in its provisions for women who want time off to have babies...英國在婦女生育福利方面依然落后于歐洲大多數國家。The restructuring of the pattern of consumption in Britain also lagged behind...在消費結構重組方面，英國也落后于人。
N-COUNT
間隔；間歇；時間差
A time lag or a lag of a particular length of time is a period of time between one event and another related event.
例句
There's a time lag between infection with HIV and developing AIDS...從感染艾滋病病毒到病發有一段滯后期。Price rises have matched rises in the money supply with a lag of two or three months.在增加貨幣供應兩三個月后，物價也跟著上漲。
VERB
給（屋頂、水管或水箱）裝絕熱層
If you lag the inside of a roof, a pipe, or a water tank, you cover it with a special material in order to prevent heat escaping from it or to prevent it from freezing.
例句
If you have to take the floorboards up, take the opportunity to lag any pipes at the same time...如果一定要把地板掀開，不妨趁此機會給各個管道加一層隔熱保護。Water tanks should be well lagged and the roof well insulated.水箱和屋頂都需要敷設嚴密的保溫層。