WordWeb Online

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

See also: likely, nonexempt, responsible, susceptible

Encyclopedia: Liable