underside

n.底面，下侧

undermanned, undermentioned, undermine, undermined, underneath, undernourished, undernourishment, underpants, underpass, underpay, underpin, underplay, underprivileged, underrate, underscore, undersea, underseal, undersell, undershirt, undershorts, undersigned, undersized, underslung, undersold, understaffed, understand, understandable, understandably, understanding, understate, understated, understatement, understood, understudy, undertake, undertaker, undertaking, undertone, undertow, underutilize,