Excited about ten-cent deposit (8)
I believe the answer is:
sediment
'deposit' is the definition.
(I know that deposit can be written as sediment)
'excited about ten-cent' is the wordplay.
'excited' becomes 'sent' (send can mean to excite or stimulate).
'about' means one lot of letters goes inside another.
'ten-cent' becomes 'dime' (I can't justify this - if you can you should believe this answer much more).
'sent' going around 'dime' is 'SEDIMENT'.
Can you help me to learn more?
(Other definitions for sediment that I've seen before include "Dregs; deposit" , "Matter settling (on seabed)" , "Residue" , "Matter settling out in liquid" , "Remains" .)