Awkward but lots of fun and widely used (8)
I believe the answer is:
unwieldy
'awkward' is the definition.
(similar in meaning)
'lots of fun and widely used' is the wordplay.
'lots of fun' becomes 'un' (I can't justify this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'used' indicates an anagram.
'widely' with letters rearranged gives 'wieldy'.
'un'+'wieldy'='UNWIELDY'
'but' is the link.
Can you help me to learn more?
(Other definitions for unwieldy that I've seen before include "Hard to manage" , "Awkward to move because of shape and weight" , "Ponderous" , "Cumbersome" , "Large and awkward to carry or manage" .)