( ( Alternating current ) ( ( -LRB- ( ac -RRB- ) ) ( '' ( ( means ( ( electrical current ) ( that ( ( reverses direction ) ( in ( ( a circuit ) ( at ( regular intervals ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (NP (NN Alternating) (JJ current)) (PRN (-LRB- -LRB-) (NP (NN ac)) (-RRB- -RRB-)) ('' '') (VP (VBZ means) (NP (NP (JJ electrical) (NN current)) (SBAR (WHNP (WDT that)) (S (VP (VBZ reverses) (NP (NN direction)) (PP (IN in) (NP (NP (DT a) (NN circuit)) (PP (IN at) (NP (JJ regular) (NNS intervals)))))))))) (. .)))
Alternating current (ac)&quot; means electrical current that reverses direction in a circuit at regular intervals.
(ROOT (S (NP (VBG Alternating) (NN current)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (JJ electric) (NN current))) (SBAR (WHNP (WDT that)) (S (VP (VBZ keeps) (S (VP (VBG reversing) (NP (NN direction))))))))) (. .)))