Two creatures together that might stop leaks (7)
I believe the answer is:
sealant
'that might stop leaks' is the definition.
(sealant might seal up a leak)
'two creatures' is the wordplay.
'two creatures' means two replacements for 'creature'.
'creature' becomes 'seal' (type of animal).
'creature' becomes 'ant'.
'seal'+'ant'='SEALANT'
'together' acts as a link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for sealant that I've seen before include "Material stopping leaks" , "Material blocking leaks" , "Material for plugging leaks" , "Bond" , "Substance for closing something tightly" .)