Soft, but it will get stronger (3)
I believe the answer is:
wax
'it will get stronger' is the definition.
The definition suggests a singular noun which matches the answer.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for wax that I've seen before include "Grow large" , "Cere - grow larger" , "It forms in the ear" , "Substance in candles" , "Substance found in ears, or in some museums" .)