Persuade alien to visit Earth (3,5)
I believe the answer is:
get round
'persuade' is the definition.
Both the definition and answer are verbs in their base form.
Perhaps you can see a link between them that I can't see?
'alien to visit earth' is the wordplay.
'alien' becomes 'et' (extra terrestrial).
'to visit' indicates putting letters inside (inserted letters visit others).
'earth' becomes 'ground' (synonyms).
'et' put into 'ground' is 'GET ROUND'.
Can you help me to learn more?
(Other definitions for get round that I've seen before include "Evade (a restriction)" , "Coax to become circular?" , "Influence in one's favour, coax (3,5)." , "Avoid" , "Influence in one's favour or circumvent" .)