Question

By chucking the word unrelenting into its roots, prefix, and suffix, we can determine that it means

a. not available for rent
b. the act of not letting up
c. the act of not borrowing
d. not being borrowed

Answer 1

b. the act of not letting up

Answer 2

The common usage of unrelenting is a determined pursuit of a goal without letting up.

un - means not
relent comes from middle english/latin meaning slow flowing

ing is the verb form (participle)

So the meaning is not easily flowed or not letting up.

His pain was unrelenting all day long.
Pain never let up.