prior

distinguished, eminent, illustrious, noble, notable, noteworthy, outstanding, prestigious, signal, star, stellar, superior

high-level, senior, top

important, influential, major, mighty, momentous, significant

incomparable, matchless, unequaled (or unequalled), unparalleled, unsurpassed

celebrated, famed, famous, renowned

advance, early, premature

earliest, first, inaugural, initial, maiden, original, pioneer

preexisting

introductory, preliminary

erstwhile, whilom