词根：-vac-, -vacu-, -van-, -void-

【词根含义】：空

【词根来源】：-vac-来源于拉丁语动词vac.o, vac.are, vac.avi, vac.atum(空);-vacu-来源于拉丁语动词vacuo, -are, -avi, -atus(使空); -van-来源于拉丁语形容词van.us, van.a, van.um(空);-void-来源于古法语vuide(空的)。均可追溯至原始印欧语wan-(缺乏的)。

【同源单词】：vacancy, vacant, vacate, vacation, vacationist

词根词缀：cresc-, -cret, -crease

【来源及含义】Latin: to become greater or larger in amount or size, to grow, to multiply; to reproduce

【相关描述】The words in this cresc- unit are closely related to the creat- unit.

【同源单词】accretion, accretion disk, accretive, accrue, accrued, concrete