A mirror that is partially reflective and partially transparent

plural of one-way mirror

(idiomatic) To move forward, usually toward a destination or goal, physically or conceptually.

(idiomatic) To be adequate or helpful for a significant amount of time. / (idiomatic) To achieve considerable success.

(idiomatic) To make significant progress.

(idiomatic, euphemistic) To engage (as the more active or dominant partner) in sexual intercourse with, especially without the consent of one's partner; rape

plural of wrong-way concurrency

(astronomy) The galaxy in which Earth and the rest of the Solar System is located.

A street in which traffic is allowed to proceed in two directions. / (idiomatic) Any interaction in which both parties give and take equally.

To become lost; to lose one's bearings, or idea of where one is. / (figuratively) To cease to succeed or to follow the right path; to fail.