nasilno

1. violently; by force; forcibly
   Lopovi su nasilno ušli u stan. — The burglars broke into the flat by force.
   Vrata su bila nasilno otvorena. — The door had been forced open.
2. (of interpretations, links) artificially; in a forced, strained way
   Autor nasilno povezuje događaje koji nemaju veze jedan s drugim. — The author artificially links events that have nothing to do with each other.

A forced smile or laugh is usiljeno (usiljeno se nasmejao), not nasilno.