Similarity in Sound
The similarity in sound option lights up whenever the intelligent rhyme is chosen from the rhyme type menu. It allows you to influence the closeness of a rhyme by tapping/clicking on the '≈' and '=' buttons. The gap in the circular line around the center button indicates the degree of similarity in sound.
Each change in the similarity in sound will give you more phonetically related near rhymes without repeating prior rhyme mates.