almost 指在程度上相差很小，差不多。
nearly 与almost含义基本相同，侧重指数量、时间或空间上的接近。
about 常可分almost和nearly换用，但about用于表示时间、数量的“大约”时，实际数量可能多也可能少。
approximately 多用于书面语，指精确度接近某个标准以致误差可忽略不计。
around 多用于非正式场合，常见于美国英语。
roughly 指按精略估计，常代替about。
参考例句
1. He played roughly with the baby. 他粗鲁地与这个婴儿玩耍。
2. Do not disassemble or handle the shave roughly. 不要拆卸或粗暴地操作电动剃须刀。
3. However, this is not all children, only those whom are embodying dragon souls and whom have agreements to ascend, which is roughly 1% of the current newborns in any given year. 但是，不是所有的孩子们都这样，只有那些包含入龙灵魂和有提升协议的孩子是被如此配备，在特定的年份中，大概占当时新生儿的1%。
英英解释
adv.
1. (of quantities) imprecise but fairly close to correct
2. with roughness or violence (`rough' is an informal variant for `roughly')
3. with rough motion as over a rough surface
