Charges unreasonable rates (5)

I believe the answer is:
tears
'charges' is the definition.
('tear' can be a synonym of 'charge')
'unreasonable rates' is the wordplay.
'rates' anagrams to 'TEARS'.
However, I am not clear how this is indicated.
Can you help me to learn more?
(Other definitions for tears that I've seen before include "Globules of ocular moisture" , "Show of emotion" , "See 12" , "charges" , "Rips; droplets" .)
