base — The base of something is its lowest edge or part.
bottom — The bottom of something is the lowest or deepest part of it.
foot — (in vertebrates) the terminal part of the leg, below the ankle joint, on which the body stands and moves.
nadir — Astronomy. the point on the celestial sphere directly beneath a given position or observer and diametrically opposite the zenith.
anticlimax — You can describe something as an anticlimax if it disappoints you because it happens after something that was very exciting, or because it is not as exciting as you expected.
cliffhanger — A cliffhanger is a situation or part of a play or film that is very exciting or frightening because you are left for a long time not knowing what will happen next.
