Force don to tour university (6)
I believe the answer is:
duress
'force' is the definition.
(duress is a kind of force)
'don to tour university' is the wordplay.
'don' becomes 'dress' (to don something is to dress in it).
'to tour' means one lot of letters goes inside another (to tour can mean to go around).
'university' becomes 'U' (abbreviation for university).
'dress' placed around 'u' is 'DURESS'.
(Other definitions for duress that I've seen before include "Coercion, pressure" , "Use of force or threats, often vile" , "Illegal coercion" , "The use of force or threats to get one's way" , "Restraint" .)