noun
: a surveyor's compass with a vernier by means of which a compensating adjustment may be made for magnetic variation to enable the reading of the correct bearings directly from the compass
noun
: a surveyor's compass with a vernier by means of which a compensating adjustment may be made for magnetic variation to enable the reading of the correct bearings directly from the compass
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012