GONIOMETER
goniometer
(noun) direction finder that determines the angular direction of incoming radio signals
Source: WordNet® 3.1
Etymology
Noun
goniometer (plural goniometers)
A device used to measure the angles of joints commonly used in orthopedics and physical therapy.
A device used to measure the angles of crystals.
A radio direction finder.
(medicine) An arthrometer (device for measuring the arc or range of mobility of a joint).
Source: Wiktionary
Go`ni*om"e*ter, n. Etym: [Gr. -meter: cf. F. goniomètre.]
Definition: An instrument for measuring angles, especially the angles of
crystals, or the inclination of planes. Contact, or Hand, goniometer,
a goniometer having two movable arms (ab, cd), between which (at ab)
the faces of the crystals are placed. These arms turn about a fixed
point, which is the center of the graduated circle or semicircle upon
which the angle is read off.
– Reflecting goniometer, an instrument for measuring the angles of
crystals by determining through what angular space the crystal must
be turned so that two rays reflected from two surfaces successively
shall have the same direction; -- called also Wollaston's goniometer,
from the inventor.
Source: Webster’s Unabridged Dictionary 1913 Edition