Unifilar \U`ni*fi"lar\, a. [Uni- + L. filum a thread.]

Having only one thread; involving the use of only one thread, wire, fiber, or the like; as, unifilar suspension.

Unifilar magnetometer (Physics), an instrument which consists of a magnetic bar suspended at its center of gravity by a long thread, constituting a delicate means for accurately measuring magnetic intensities, also for determining declinations of the magnetic needle.

Source: Webster's Revised Unabridged Dictionary (1913)