Teach me to fashion knife (7)
I believe the answer is:
machete
'knife' is the definition.
(machete is a kind of knife)
'teach me to fashion' is the wordplay.
'to fashion' indicates anagramming the letters.
'teach'+'me'='teachme'
'teachme' is an anagram of 'MACHETE'.
(Other definitions for machete that I've seen before include "A heavy-duty jungle knife" , "Broad heavy knife common in Central America" , "Heavy South American knife" , "hacker" , "Jungle chopper" .)