ad.

1. （朝同一方向）並列，並排
   Read the papers if you want to keep abreast of the times.

   你想跟上時代就得讀報。

2. 並肩
   They walked home two abreast.

   他倆肩並肩地走回家去。

adv.

1. side by side and facing the same way.
2. alongside.
3. (abreast of) up to date with.