ˈrāˌdär, -dȧ(r noun
( -s )
Usage: often attributive
Etymology: ra dio d etecting a nd r anging
: a radio device or system for locating an object by means of emitting radio signals usually in the form of pulses of an ultrahigh frequency and observing and analyzing the minute signals reflected from the object and received at or near the point of transmission in such a way that range, bearing, and other characteristics of the object may be determined