The word "in-adept" refers to a lack of skill or incompetence in a particular area. Its antonyms, however, are words that describe proficiency or expertise in a given field. Some antonyms of "in-adept" include "proficient," "skilled," "adept," "expert," "experienced," "fluent," "competent," "masterful," "accomplished," "talented," "gifted," and "capable." These words indicate a level of ability and knowledge that is diametrically opposed to "in-adept." Therefore, if you're looking to describe someone who is proficient in a particular area, you can use one of these antonyms of "in-adept.