Clean around top of teapot's spout (5)
I believe the answer is:
erupt
'spout' is the definition.
(I've seen this before)
'clean around top of teapot's' is the wordplay.
'clean' becomes 'pure' (similar in meaning).
'around' says the letters should be written in reverse.
'top of' says to take the initial letters.
The initial letter of 'teapots' is 't'.
'pure' written backwards gives 'erup'.
'erup'+'t'='ERUPT'
(Other definitions for erupt that I've seen before include "spout" , "Break out suddenly and violently" , "suddenly burst out" , "Emit lava" , "Burst forth, like 25" .)