WordNet sense 1 (the point in time at which something ends):

end

WordNet sense 2 (time between the beginning and the end of a temporal period):

middle

WordNet sense 3 (a part or voice or instrument or orchestra section lower in pitch than or subordinate to the first):

second

WordNet sense 4 (lying between two extremes in time or space or degree):

intermediate, intermediate

WordNet sense 5 (coming after all others in time or space or degree or being the only one remaining):

last