关于蜥蜴的英文命名

Question

请教一下各位高手，为什么很多蜥蜴的英文名字里叫monitor，比如美洲毒蜥蜴叫lace monitor，一种巨蜥叫crocodile monitor？谢谢各位了！
能否在讲些词源？
好失望，wiki里面直接黏贴过来的，请高人解惑，悬赏分好说。

Answer 1

monitor有大壁虎, 巨蜥的意思。

Answer 2

Monitor lizards also known as bayawak or goannas, genus Varanus, are members of the family Varanidae. Varanus is a group of carnivorous lizards which includes the heaviest living lizard, the Komodo dragon and the crocodile monitor which is the longest lizard in the world. The closest living relatives the are the anguid and helodermatid lizards.[1]