Char wraps your medical instrument (7)
I believe the answer is:
syringe
'medical instrument' is the definition.
(I know that syringe is a type of medical instrument)
'char wraps your' is the wordplay.
'char' becomes 'singe' (I've seen this before).
'wraps' means one lot of letters goes inside another (inserted letters get wrapped up).
'your' becomes 'yr' (shortened version of 'your' in eg textspeak).
'singe' enclosing 'yr' is 'SYRINGE'.
(Other definitions for syringe that I've seen before include "Inoculator's instrument" , "jabber?" , "Device for giving injections" , "Instrument for injections" , "Medical instrument" .)