gravamen
/grəˈveɪmen/noun
(pl.gravamina /-mɪnə/)
1- chiefly Law the essence or most serious part of a complaint or accusation【主律】（诉状中的）控诉要旨; 投诉要点。
1.1
- a grievance冤情; 委屈。
词源
early 17th cent. (as an ecclesiastical term denoting formal presentation of a grievance)： from late Latin， literally 'physical inconvenience'， from Latin gravare 'to load'， from gravis 'heavy'.