attack

"on the attack,"

making an attack:
The soldiers were on the attack.

—often used in the phrase go on the attack with the meaning "to begin attacking":
Last week he challenged Bradley to debate him and went on the attack, accusing his challenger of "disloyalty" to the party... —Matt Bai.

"under attack,"

1. in the process of being attacked:
soldiers under attack; a politician who is under attack from his opponents.

—often used in the phrase come under attack with the meaning "to begin being attacked":
a theory that has recent come under attack.

Origin:

1590–1600; earlier atta(c)que < Middle French atta(c)quer < Italian attaccare to attack, attach. British dictionary: C16: from French attaquer, from Old Italian attaccare to attack, attach, from estaccare to attach, from stacca stake 1; compare attach. —Dictionary.com. //

First Known Use of attack: Verb: circa 1576. Noun: 1655. Adjective: 1686. History and Etymology for attack: Verb, Noun, and Adjective: Middle French attaquer, from Old Italian *estaccare to attach, from stacca stake, of Germanic origin; akin to Old English staca. —Merriam-Webster.

Sources: 1, 2.

Updated: 1 August 2020 {8:33 AM}