Nurse touching tissue (6)
I believe the answer is:
tendon
'tissue' is the definition.
(tendon is a kind of tissue)
'nurse touching' is the wordplay.
'nurse' becomes 'tend' (tend can mean to nurse or look after).
'touching' becomes 'on' ().
'tend'+'on'='TENDON'
(Other definitions for tendon that I've seen before include "horse's hamstring" , "Strong cord of tissue connecting muscle" , "personal connecting link" , "Tissue connecting a muscle with its bony attachment" , "Ligament - sinew" .)