相关单词近义词 down 向下, underground 地下的临近词undersea, under, underwinding, Under Collar, undercurrent, underperform, underseepage, undergarment, underservant, undertrained, undersanding, under canvas相似词underemployed, underestimate, underexpose, underfloor, underfunded, undergarment, undergird, undergo, 返回 underfoot