Brood holding egg of timid creature (5)
I believe the answer is:
mouse
'timid creature' is the definition.
(I've seen this before)
'brood holding egg' is the wordplay.
I cannot really understand how this works, but
'egg' could be 'o' (an 'o' resembles an egg) and 'o' is located in the answer.
The remaining letters 'muse' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for mouse that I've seen before include "Small rodent - computer attachment" , "black eye" , "Small verminous rodent" , "Computer accessory" , "Timid fellow" .)