Diameter
Diameter was the geometrical straight line through a circular object. It could specify the object's dimension.

In June of 2151, Captain Jonathan Archer told Andorian Commander Thy'lek Shran that a man in Canton, Ohio had once rolled a ball of string six meters in diameter. ()

The diameter of "Archer's Comet" was 82.6 kilometers, according to T'Pol's readings. ()

Following her scans of the debris of the alien ship found in the Arctic Circle,  identified it as spherical and about six- meters in diameter. ()

In 2265, Lee Kelso measured the unknown object later to be identified as the 's ejected disaster recorder to be approximately one meter in diameter. () 

In 2266, Spock estimated the diameter of the Fesarius to be one mile. ()

In 2267, James T. Kirk claimed over a Code 2 transmission that the auto-destruct initiated by a "corbomite device" would destroy all matter within a two hundred thousand kilometer diameter, a clever bluff to fool the Romulans. ()

The nucleogenic cloud being encountered by the  in 2371 measured seven au in diameter. ()

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Mathematics