Crane moving bit of shell (5)
I believe the answer is:
'bit of shell' is the definition.
'nacre' can be an answer for 'shell' (nacre is a kind of shell). I am unsure of the 'bit of' bit.
'crane moving' is the wordplay.
'moving' indicates anagramming the letters (letters are moved around).
'crane' is an anagram of 'NACRE'.
Can you help me to learn more?
(Other definitions for nacre that I've seen before include "Constituent of inlay furniture" , "inside of shell" , "Mother of pearl" , "Mother-of-pearl - crane (anag)" , "Mother-of-pearl from shellfish" .)