WordWeb Online

1. Having rugged physical strength; inured to fatigue or hardships
   "sturdy young athletes"
   - hardy, stalwart, stout
    
2. Not making concessions
   - uncompromising, inflexible
    
3. Substantially made or constructed
   "sturdy steel shelves"; "sturdy canvas"
   - tough

Derived forms: sturdiest, sturdier

See also: hardline, hard-line, robust, rugged, sturdily, sturdiness