Definition of "aftermost"

All the after-most part of the ship, is called the sterne (by a generall appellation) but most exactly considered, only the very outwardmost part abaft is the sterne;

1644, Henry Manwayring, The Sea-mans Dictionary‎, London: John Bellamy, page 101

My station during the engagement was on the middle-deck, where I was quartered with another boy, to bring powder to the aftermost gun;

1789, Olaudah Equiano, chapter 4, in The Interesting Narrative of the Life of Olaudah Equiano‎, volume 1, London, page 148

[…] at night I slept on a blanket thrown on the deck boards at the aftermost end of the round-house, and right in the draught of the two doors.

1886 May 1 – July 31, Robert Louis Stevenson, “chapter 8”, in Kidnapped, being Memoirs of the Adventures of David Balfour in the Year 1751: […], London, Paris: Cassell & Company, published 1886, page 68

In this sense Aristotle’s words hold good, if he refer the former part of the fourth species to the after-most times and ultimat center of Heroicisme, and the latter part to the prior, though not to the first times thereof.

1653, Peter English, The Survey of Policy, Leith, Section 1, Subsection 1, p. 99

Now whiles I was taken up with these anxious thoughts, a messenger […] came to me from the Lord Denny […] , my after-most Honourable Patron, entreating me from his Lordship to speak with him.

1663, Clement Barksdale, Memorials of Worthy Persons‎, Oxford, page 78

And he put the handmaids and their children, first: and Leah and her children, after; and Rachel and Ioseph, aftermost.

1627, Henry Ainsworth, Annotations upon the Five Bookes of Moses, the Booke of the Psalmes, and the Song of Songs‎, London: John Bellamy, Genesis 33, page 122