r) KEY NOUN:
Abbr. d or diam. Mathematics
- A straight line segment passing through the center of a figure, especially of a circle or sphere, and terminating at the periphery.
- The length of such a segment.
- Thickness or width.
- A unit for measuring the magnifying power of a microscope lens or telescope, equal to the number of times an object's linear dimensions are apparently increased.
Middle English diametre
, from Old French, from Latin diametrus
, from Greek diametros (gramm)
, diagonal (line)
; see m-2
in Indo-European rootsOTHER FORMS:di·ame·tral
l) KEY (Adjective)