What is "bifilar"

Bifilar \Bi*fi"lar\, a. [Pref. bi- + filar.] Two-threaded; involving the use of two threads; as, bifilar suspension; a bifilar balance.

Bifilar micrometer (often called a bifilar), an instrument form measuring minute distances or angles by means of two very minute threads (usually spider lines), one of which, at least, is movable; -- more commonly called a filar micrometer.

a. Having two wires, threads or filaments

adj. having or using two filaments; "a bifilar suspension of a waving part of an instrument"