Pretend a broken finger has the end missing! (5)
I believe the answer is:
feign
'pretend' is the definition.
(I know that pretend can be written as feign)
'a broken finger has the end missing' is the wordplay.
'a broken finger' becomes 'fein' (I can't explain this - if you can you should give a lot more credence to this answer).
'has' indicates putting letters inside.
'the end' indicates one should take the final letters.
The last letter of 'missing' is 'g'.
'fein' enclosing 'g' is 'FEIGN'.
Can you help me to learn more?
(Other definitions for feign that I've seen before include "Pretend, simulate" , "Pretend to experience" , "Pretend to be affected by" , "Make a pretence of" , "outdated shape" .)