Verb (1-dan, intransitive)
1. to be sufficient; to be enough
だが、それだけでは足りないものもある。However, there are some things for which that alone is not enough.
2. to be worth doing; to be worthy of; to deserve
in the form に足りる after a verb
それは驚くに足りない。That's nothing to be surprised about.
3. to do (the job); to serve; to answer
わざわざ来なくても電話で足りるよ。You don't need to come all the way here; a phone call will do.