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• A one
  A one

  adjective

  noting a vessel regarded by a shipping-classification society as being equipped to the highest standard and with equipment maintained in first-class condition.
• A-one
  A-one

  Also, A-1; A-number-one. First-class, of the best quality, as in This is an A-one steak. The term comes from Lloyd's, the British insurance company, which in its 1775 shipping register designated the condition of a ship's hull by a letter grade (A, B, etc.) and of its cables, anchor, and other equipment by a number grade (1, 2, etc.). By the early 1800s A-1, the best possible grade, was being transferred to anything of superior quality.

A one

American  

[ey wuhn] / ˈeɪ ˈwʌn /

Also A-one,

adjective

1. noting a vessel regarded by a shipping-classification society as being equipped to the highest standard and with equipment maintained in first-class condition.

2. Informal. Also A number one. first-class; excellent; superior.

   The meals there are A one.

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A-one Idioms  

1. Also, A-1; A-number-one. First-class, of the best quality, as in This is an A-one steak. The term comes from Lloyd's, the British insurance company, which in its 1775 shipping register designated the condition of a ship's hull by a letter grade (A, B, etc.) and of its cables, anchor, and other equipment by a number grade (1, 2, etc.). By the early 1800s A-1, the best possible grade, was being transferred to anything of superior quality.

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Etymology

Origin of A one

First recorded in 1830–40

Example Sentences

See Examples For:

A one A-one

A one star review from The Washington Post called it as "a very special kind of hell".

From BBC ● Jun. 8, 2025

A "one size fits all" approach won't do.

From Salon ● Jul. 27, 2023

A one of a kind mural can elevate your space to another level of sophistication, Ament says.

From Seattle Times ● Feb. 24, 2023

A one thousand Argentine pesos bill is shown inside a store, in Buenos Aires, Argentina July 29, 2022.

From Reuters ● Jul. 29, 2022

The hull sat on Panel A, one of four sides of the tetrahedron which brought Pathfinder to Mars.

From "The Martian" by Andy Weir

“Here, Tessie, take Callie’s leg. Okay, on three. A-one and a-two and a-three!”

From "Middlesex: A Novel" by Jeffrey Eugenides

"You'll make an A-one bake in the New Hebrides."

From The Wrecker by Stevenson, Robert Louis

After which speech he felt that everything was all right—everything was A-one.

From Aaron's Rod by Lawrence, D. H. (David Herbert)

He's ce'tainly got an A-one rep. as a cattle detective, and likewise as a man hunter.

From Mavericks by Raine, William MacLeod

Thar's mother—full suit of sail, rated a hundred A-one at Lloyd's, the most important sheep in the Lord's flock.

From A Man in the Open by Pocock, Roger