Intermediacy is a noun that refers to the state of being intermediate or in the middle. It's an essential concept in many fields, especially in science, mathematics, and business. However, in language, it's essential to understand antonyms, words that mean the opposite of the given word. For intermediacy, some antonyms include extremity, finality, and extremeness. Extremity means the state of being at the opposite end or farthest point from the center or middle. Finality, on the other hand, means the state of being conclusive or decisive, indicating that there is no further negotiation or compromise. Lastly, extremeness means the state of being extreme, indicating that something is going beyond the usual or reasonable limits.