What does "abreast" mean?

Abreast: (Naut.) Side by side; also, opposite; over against; on a line with the vessel's beam; -- with of.

Additional senses

  1. 2.Up to a certain level or line; equally advanced; as, to keep abreast of [or with] the present state of science.
  2. 3.At the same time; simultaneously. [Obs.] Abreast therewith began a convocation. Fuller.

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