Make substitute, in short, blend it and cover it with water (8)
I believe the answer is:
submerge
'make' is the definition.
The definition and answer can be both to do with motion as well as being verbs in their base form.
Perhaps you can see a link between them that I don't see?
'substitute in short blend it and cover it with water' is the wordplay.
I cannot really see how this works, but
'substitute' could be 'sub' (synonyms) and 'sub' is present in the answer.
'blend' could be 'merge' (synonyms) and 'merge' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for submerge that I've seen before include "Place below water, flood" , "swill round" , "Sink - inundate" , "(Submarine) dive" , "Duck" .)