semidiameter

English

Etymology

From Middle English semidiametre, semydiametre, from Medieval Latin sēmidiameter, equivalent to semi- +‎ diameter.

Noun

semidiameter (plural semidiameters)

1. (astronomy) The apparent radius of a star etc, when viewed from Earth.
2. (archaic) A radius: half of a diameter.

Derived terms

• semidiameter correction