WordWeb Online

1. Not placed under psychological stress
   "the campaign would not leave party loyalties unstrained"
    
2. Not resulting from undue effort; not forced
   "his playing is facile and unstrained"
   - unforced

1. Cause to feel relaxed
   "A hot bath always unstrains me"
   - relax, unlax, loosen up, unwind, make relaxed

See also: effortless, relaxed

Type of: affect

Antonym: strain