1. Held legally responsible
   "men between the ages of 18 and 35 were liable for military service"
    
2. Subject to legal action
   "liable to criminal charges"
    
3. At risk of or subject to experiencing something usually unpleasant
   "she is liable to forget";
   - apt
    
4. (often followed by ‘to’) likely to be affected with
   "liable to diabetes";
   - nonimmune, nonresistant, unresistant

See also: likely, nonexempt, responsible, susceptible

Encyclopedia: Liable