(rare) Tending to keep oneself separate from others.
noun
Something that serves to separate.
1853, A. F. Lendy, The Principles of War, London: Parker, Furnivall, and Parker, “Strategy,” Chapter 4, p. 117,
[…] as for the distance between [the roads], it varies according to the strength of the army and the nature of the ground, the essential point being not to leave between them obstacles acting as separatives, such as rivers, &c.