The Clue Unit of opinion?
The Answer CENT
The answer "CENT" fits the clue "Unit of opinion" because a "cent" is a unit of currency. In a figurative sense, people often say "I'll give you my two cents" when sharing their opinion. This phrase implies that everyone has something to contribute, just like how cents add up to make a whole. Thus, "cent" cleverly connects the idea of a unit to expressing opinions.