Brush his tail and cry (5)
I believe the answer is:
sweep
'brush' is the definition.
(I know that brush can be written as sweep)
'his tail and cry' is the wordplay.
'his tail' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'and' says to put letters next to each other.
'cry' becomes 'weep' (synonyms).
's'+'weep'='SWEEP'
Can you help me to learn more?
(Other definitions for sweep that I've seen before include "gambling event" , "Brush; rush" , "Row" , "Use broom; Sooty's friend" , "Long oar" .)