halfnutn.对开螺母halfn.一半；下半场；半学年adj.一半的；不完全的adv.一半地；不完全地half tone positive半色调正片half-shade plate半影板half-word buffer半字缓冲器half cell reaction半电池反应half-band filter半带滤波器half diesel engine半柴油发动机half-line period半行周期half track tractor半履带式拖拉机,半链轨式拖拉机half-fare ticket半票half side formulas半边公式