/ ˈfɪləmənt; NAmE / noun
1.
a thin wire in a light bulb that produces light when electricity is passed through it
2.
(especially technical ) a long thin piece of sth that looks like a thread :
glass / metal filaments
••
WORD ORIGIN
late 16th cent.: from French , or from modern Latin filamentum , from late Latin filare to spin, from Latin filum thread.