The noun ambiguity can be countable or uncountable. In more general, commonly used, contexts, the plural form will also be ambiguity. However, in more specific contexts, the plural form can also be ambiguities e.g. in reference to various types of ambiguities or a collection of ambiguities.

What is the plural of ambiguous?

ambiguity /ˌæmbəˈgjuːwəti/ noun. plural ambiguities.

Is ambiguity countable or uncountable?

1[uncountable] the state of having more than one possible meaning Write clear definitions in order to avoid ambiguity. A lot of humor depends on ambiguity. 2[countable] a word or statement that can be understood in more than one way There were several inconsistencies and ambiguities in her speech.