Disambiguation refers to the removal of ambiguity by making something clear. Disambiguation narrows down the meaning of words and it's a good thing.
This word makes sense if you break it down. Dis means "not," ambiguous means "unclear," and the ending -tion makes it a noun. So disambiguation is the act of making something clear. Disambiguation distinguishes between different meanings of words. If you say the word joker, do you mean a playing card, a prankster, or a Batman villain? Disambiguation will clear things up. If you mention that you were playing poker, then it's clear which joker you're talking about. When you see the word disambiguation, think "clearing up confusion."