Leaders of English battalions boldly suggesting retreats (4)
I believe the answer is:
ebbs
'retreats' is the definition.
(I know this)
'leaders of english battalions boldly suggesting' is the wordplay.
'leaders of' suggests taking the first letters.
The first letters of 'english battalions boldly suggesting' is 'EBBS'.
(Other definitions for ebbs that I've seen before include "flags" , "Wanes" , "Flows back or recedes" , "fades away" , "Subsides" .)