Fine....

am⋅bi⋅dex⋅trous
   /ˌæmbɪˈdɛkstrəs/ Show Spelled Pronunciation [am-bi-dek-struhs] Show IPA Pronunciation
–adjective
1. able to use both hands equally well: an ambidextrous surgeon.
Source: Dictionary.com

Either way, the official definition says EQUALLY well, of course, my first source was Wikipedia, which is probably not the best source. I think to some people it has become acceptable to use the word ambidextrous for people who have one or more skills on their secondary hand, like a left handed person batting right handed in baseball.

This is NOT ambidextrous, ambidextrous is EQUAL in both hands, which is extremely rare. Alot of people are primary on one side and can do some things with the other hand.