Yours truly twice getting pound in return for symbol (6)
I believe the answer is:
emblem
'for symbol' is the definition.
(emblem is a kind of symbol)
'yours truly twice getting pound in return' is the wordplay.
'yours truly' becomes 'me' (the person who set this crossword).
'twice' becomes 'me' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'getting' indicates putting letters inside.
'pound' becomes 'lb' (abbreviation for the unit of weight).
'in return' shows that the letters should be reversed in order (return can mean to go backwards).
'me'+'me'='meme'
'meme' going around 'lb' is 'melbme'.
'melbme' reversed gives 'EMBLEM'.
Can you help me to learn more?
(Other definitions for emblem that I've seen before include "Device, badge or symbol" , "Symbol; heraldic device" , "Badge or representative device" , "Symbol, representative device" , "Symbol, representing a country say" .)