Rested on the bottom (3)
I believe the answer is:
sat
'rested' is the definition.
(to sit is to rest)
'on the bottom' is the wordplay.
'on' says to put letters next to each other.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'bottom' becomes 'sa' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
't' put after 'sa' is 'SAT'.
Can you help me to learn more?
(Other definitions for sat that I've seen before include "Took a chair" , "Was in session" , "Pulled up a 29 down" , "Was sitting" , "twenty-four hours" .)