38 synonyms for preliminary such as opening, advance, groundwork, introduction, and opening/prefatory remarks. Preliminary is an adjective, and its antonyms are concluding, closing, and final.
Advance, early, eliminating, experimental, explorative, exploratory, initial, initiatory, introductory, lead-in, opening, pilot, preceding, precursive, precursory, prefatory, preludial, prelusive, prelusory, preparatory, prior, prodromal, prodromic, qualifying, test, and trial.
First round, groundwork, overture, preliminary action, prelude, and preparation.
Formalities, introduction, opening, opening/prefatory remarks, and preamble.