Verb (5-dan, く, intransitive)
1.  to be effective;  to take effect;  to be good (for)
usu. 効く
2.  to work;  to function well
usu. 利く for body senses, functions, etc.
3.  to be possible (to do, use, etc.);  to be able to
Verb (5-dan, く, transitive)
4.  to taste (alcohol);  to try