Egg protected by four geese (4)
I believe the answer is:
urge
'egg' is the definition.
(I've seen this before)
'protected by four geese' is the wordplay.
'protected by' says the answer is hidden in the clue.
'URGE' is hidden in the letters of 'four geese'.
(Other definitions for urge that I've seen before include "'Spur on, encourage (4)'" , "Strongly recommend; impulse" , "Incite to action" , "Advocate" , "Appeal to" .)