Cook starts to serve someone piece of cake (4)
I believe the answer is:
doss
'piece of cake' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how they can define each other.
'cook starts to serve someone' is the wordplay.
'cook' becomes 'do' (do can mean to cook).
'starts to' suggests taking the first letters.
The initial letters of 'serve someone' is 'ss'.
'do'+'ss'='DOSS'
Can you help me to learn more?
(Other definitions for doss that I've seen before include "Sleep in a makeshift bed" , "going off to sleep" , "go to bed" , "Sleep - sleeping place" , "Sleep (in cheap lodgings?)" .)