With which each grebe generally starts? (3)
I believe the answer is:
egg
'with which' is the definition.
I can't tell whether this definition defines the answer.
'each grebe generally starts?' is the wordplay.
'starts?' says to take the initial letters (I've seen 'start' mean this).
The first letters of 'each grebe generally' is 'EGG'.
Can you help me to learn more?
(Other definitions for egg that I've seen before include "Item of food" , "nit? Just a bit!" , "Rasher to go with this" , "Over-easy breakfast item?" , "It, or chicken, first?" .)