Elutriating is a term used in science that refers to the process of separating particles or substances using a fluid. The word has no direct antonym, but one could use synonyms or related words to create antonyms. Some possible antonyms of elutriating could be "combining," "mixing," "blending," "merging," "uniting," or "amalgamating." These words signify the opposite process of elutriating, which is bringing substances or particles together instead of separating them. It's essential to understand the context in which the word is used to select the most suitable antonym.