di‧am‧e‧ter /daɪˈæmətə, daɪˈæmɪtə $ -ər/ noun [countable]
[Date: 1300-1400; Language: Old French; Origin: diametre, from Greek diametros 'measure across', from metron 'measure']
a straight line from one side of a circle to the other side, passing through the centre of the circle, or the length of this line
3 inches/1 metre etc in diameter
Draw a circle six centimetres in diameter.
diameter of
The diameter of the Earth is about 13,000 km.

[TahlilGaran] Dictionary of Contemporary English ▲

diameter
noun
ADJ. inside, internal The tubes have an internal diameter of 2mm.
external, outside | large, small
VERB + DIAMETER calculate, find, measure He used similar triangles to calculate the diameter of the earth.
have
PREP. in ~ The mirror is 25cm in diameter.

[TahlilGaran] Collocations Dictionary ▲