n. gradual change of water line on real property which gives the owner more dry land.
recession of sea leaving bare land
• (n.) A leaving dry; a recession of the sea or other water, leaving dry land; land left uncovered by such recession.
(n) Reliction is the slow draining of water level in a property resulting in clearance of additional dry land.
Re·lic'tion noun [ Latin relictio a leaving behind.] (Law) A leaving dry; a recession of the sea or other water, leaving dry land; land left uncovered by such recession. Burrill. 
The increase in land caused by the gradual recession or shrinkage of a body of water (such as a lake or sea) which gives the owner of the property more dry land.