[adv] alongside each other, facing on the same direction
[adj] beside one another in a row or rank; "they came down the street two abreast"
\A*breast"\, adv. [Pref. a- + breast.]
1. Side by side, with breasts in a line; as, ``Two men could hardly walk abreast.'' --Macaulay.
2. (Naut.) Side by side; also, opposite; over against; on a line with the vessel's beam; -- with of.
3. Up to a certain level or line; equally advanced; as, to keep abreast of [or with] the present state of science.
4. At the same time; simultaneously. [Obs.] Abreast therewith began a convocation. --Fuller.