Swelling -- not small -- daughter prodded (5)
I believe the answer is:
urged
'prodded' is the definition.
Although both the answer and definition are past participle verbs, I can't understand how one could define the other.
'swelling not small daughter' is the wordplay.
'swelling not' becomes 'urge' (I am not sure about this - if you are sure you should believe this answer much more).
'small daughter' becomes 'd' ('small' indicates an abbreviation).
'urge'+'d'='URGED'
Can you help me to learn more?
(Other definitions for urged that I've seen before include "Pressed" , "Impelled - encouraged" , "Strongly recommended" , "Beseeched" , "Exhorted or prodded" .)