Be at ease, ultimately between the tanned and the cowed (10)
I believe the answer is:
browbeaten
'cowed' is the definition.
(synonyms)
'be at ease ultimately between the tanned' is the wordplay.
'ultimately' suggests the final letters.
'between' means one lot of letters goes inside another.
'the tanned' becomes 'brown' (I've seen this before).
The final letter of 'ease' is 'e'.
'be'+'at'+'e'='beate'
'beate' placed into 'brown' is 'BROWBEATEN'.
'and the' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for browbeaten that I've seen before include "Bullied" , "Intimidated" .)