[gy.ro.com.pass] n (1910): a compass consisting of a continuously driven gyroscope whose spinning axis is confined to a horizontal plane so that the earth's rotation causes it to assume a position parallel to the earth's axis and thus point to the true north
GYROCOMPASS
Meaning of GYROCOMPASS in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012