Type of word a close friend initially misused (7)
I believe the answer is:
acronym
'type of word' is the definition.
'a close friend initially misused' is the wordplay.
'close friend' becomes 'crony' (I've seen this before).
'initially' indicates taking the first letters.
The first letter of 'misused' is 'm'.
'a'+'crony'+'m'='ACRONYM'
(Other definitions for acronym that I've seen before include "Word made from initial letters of other words" , "Word formed from initials" , "Tessa, say" , "UNICEF, perhaps" , "Perhaps nimby" .)