seisinEtymologyFrom Middle English seisin, seysen, from Old French seisin, from the verb seisir, from Early Medieval Latin sacīre, from the same Proto-Indo-European root as Gothic 𐍃𐌰𐍄𐌾𐌰𐌽 (satjan) and Old English settan. More at seize, seise.seisin means an entitlement to a freehold estate with a right to immediate possession. Lexicurio rates it Sui generis — a strength score of 89 out of 100.nounAn entitlement to a freehold estate with a right to immediate possession.The act of taking possession.The thing possessed; property.“Diſſeiſin is a large Title, and is an unlawful Entry and Ouſter of him that has an actual Seiſin and Freehold.”