Final answer:
The term that represents the ratio of the opposite side to the adjacent side in a trigonometric function is the tangent.
Step-by-step explanation:
In a trigonometric function, the term that represents the ratio of the opposite side to the adjacent side in a right triangle within the unit circle is the tangent.
In a right triangle, the opposite side and adjacent side are defined with respect to a specific angle. The tangent of an angle is defined as the ratio of the opposite side to the adjacent side, so it represents the relationship between these two sides.
For example, if we have an angle of 30 degrees in a right triangle within the unit circle, the tangent of that angle would be the ratio of the opposite side to the adjacent side.