early 15c., "stupefactive;" 1590s, "dreadful;" present participle adjective from amaze. Sense of "wonderful" is recorded from 1704. Related: Amazingly.
early 13c., amasian "stupefy, make crazy," from a-, probably used here as an intensive prefix, + -masian, related to maze (q.v.). Sense of "overwhelm with wonder" is from 1580s. Related: Amazed; amazing.