The story
Pseudo-Latinism, derived from *sēclūsīvus, a combination of sēclūdō (“to seclude”) + -īvus (“-ive”), whence the native Latin sēclūsus. Equivalent to seclude + -ive.
Etymology from Wiktionary, CC BY-SA 4.0.
seclusive
Today it means: Serving or tending to seclude (oneself); affecting seclusion. Full definition →