Answer:
The suffix of the word "imaginable" is "able".
Step-by-step explanation:
The suffix is the element that is added after the radical to modify its meaning in a word. The suffix of the word "imaginable" is "able". The word "able" refers to something that can do something. When this word makes up the word "imaginable," it brings the meaning of something that is capable of being imagined, defined, and understood.