Ambiguity (and ambiguous) comes from the Latin ambiguus, which was formed by combining ambi- (meaning "both") and agere ("to drive"). Ambidextrous combines the same prefix with dexter (meaning "skillful; relating to or situated on the right").
The sentence is using the word "was" instead of the word "were". Using "were" is appropriate for talking about the past tense for plural things. Simply change the words. Hope this helped :))
