Side by side and facing forward. / (figuratively) Alongside; parallel to. / Informed, well-informed, familiar, acquainted. / Followed by of or with: up to a certain level or line; equally advanced.

Side by side, facing forward. / (figuratively) Alongside; parallel to. / Informed, well-informed, familiar, acquainted. / Up to a certain level or line; equally advanced

Abreast of; alongside.

(nautical, military) A type of warship formation with the ships proceeding side-by-side on parallel tracks.