Try to persuade (4)
I believe the answer is:
urge
'try to persuade' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for urge that I've seen before include "Strong impulse, desire" , "'Exhort, press (4)'" , "Strong desire; impel" , "Persuade - proclivity" , "Plead" .)