Same word as zenithal:
apical, best, capital, chief, crown, head, maximal, maximum, most, paramount, preeminent, principal, superlative, supreme, tiptop, top, top-notch, uppermost, zenithal
apical, best, capital, chief, crown, head, maximal, maximum, most, paramount, preeminent, principal, superlative, supreme, tiptop, top, top-notch, uppermost, zenithal