Know how to use "fewer" and "less"? Find out.
c.1400, "uncertainty, doubt, indecision, hesitation," also from Medieval Latin ambiguitatem (nominative ambiguitas) "double meaning, equivocalness, double sense," noun of state from ambiguus (see ambiguous).
use of words that allow alternative interpretations. In factual, explanatory prose, ambiguity is considered an error in reasoning or diction; in literary prose or poetry, it often functions to increase the richness and subtlety of language and to imbue it with a complexity that expands the literal meaning of the original statement. William Empson's Seven Types of Ambiguity (1930; rev. ed. 1953) remains a full and useful treatment of the subject