Lay down rubbish, burying uranium at bottom of dump (9)
I believe the answer is:
stipulate
'lay down rubbish' is the definition.
The definition and answer can be both to do with communicating as well as being verbs in their base form.
Perhaps you can see a link between them that I don't see?
'burying uranium at bottom of dump' is the wordplay.
I cannot quite understand how this works, but
'uranium' could be 'u' (U is the chemical symbol for uranium) and 'u' is found within the answer.
'at' is present in the answer.
'dump' could be 'tip' (as in a rubbish tip) and 'tip' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stipulate that I've seen before include "Specify as an essential part" , "Make a demand" , "Define, require" , "Insist on as part of agreement" , "Demand, specify" .)