The term "avail of" means to make use of or take advantage of something. Its antonyms, which are words that have opposite meanings, include phrases such as miss out on, overlook, disregard, ignore, and neglect. When you miss out on an opportunity, you do not avail of it. Overlooking or ignoring something means to ignore its usefulness and not to avail of what it can offer you. To disregard something is to assume it is unimportant and not to avail of its value. Not availing of something because you neglect it may lead to regret in the future. It is essential to recognize these antonyms for "avail of" to avoid missing out on life's opportunities.