I believe the answer is:
'lockjaw' is the definition.
(I know that lockjaw can be written as tetanus)
This is the entire clue.
(Other definitions for tetanus that I've seen before include "Infection from wound" , "Disease causing muscular spasms" , "infectious disease" , "Attunes (anag) - muscular illness" , "Infection of the central nervous system" .)