outside diameter[机] 外径;外直径;壁厚
inside diameter[数] 内径;内部直径;内直径;内径尺寸
diameter series[机] 直径系列;直径系列
ball diameter[机] 球直径;量球直径;球直径;球径
blade diameter风轮直径;锯片直径;刀片直径;叶片直径
Speaker Diameter喇叭直径
equivalent diameter[地质] 当量直径;[数] 等效直径;平均直径
biparietal diameter双顶径;或两顶骨间之直径;胎儿双顶径;胎头双顶径
beam diameter束帘径;[光] 光束直径;束直径;光斑直径
N-COUNT（可数名词） The diameter of a round object is the length of a straight line that can be drawn across it, passing through the middle of it. 直径 [also 'in' N]
...a tube less than a fifth of the diameter of a human hair.
…一根直径不到头发五分之一的微管。