User blog comment:PerhapsTheOtherOne/Speculative Spitballing: Goliath/@comment-4010415-20150608182803/@comment-7622429-20150608195536

You're right. They did originate in the East. But there, specifically Japan, Kaiju is a much broader term, referring to anything that might be considered a "monster", regardless of size. Only in the West is a Kaiju specifically referring to a giant monster.

In the East, "daikaiju" are the contemporary giant ones.