indistinguishable

形容词 indistinguishable:

1. exactly alike; incapable of being perceived as different
   同义词：identical
2. not capable of being distinguished or differentiated
   同义词：undistinguishable

1. Its colour makes the moth indistinguishable from the branch it rests on.
   这蛾子停在树枝上，其颜色和树枝几不可辨。

in.dis.tin.guish.a.ble

adj.（形容词）
Not distinguishable, especially:
无差别的：尤指难以区分的
Impossible to differentiate or tell apart:
难分辨的：不可能去区分或识别：
例句：
indistinguishable twins; a moth with markings that make it indistinguishable from its background.
难以分辨的双胞胎；蛾翅膀上的斑纹使得它与背景无法分辨

Impossible to discern; imperceptible:
不易察觉的：不可能识别的；难以觉察的：
例句：
a sound that was indistinguishable to the human ear.
一种为人耳不易察觉的声音

Difficult to understand or make out; vague:
难以理解或辨别的；模糊的：
例句：
indistinguishable speech.
难以理解的谈话

【引伸】
in.distin.guishableness 或
in.distin.guishabil.ity
n.（名词）
in.distin.guishably
adv.（副词）