early 15c., from un- (2) "reverse, opposite of" + seal (v.). Similar formation in Middle Dutch ontsegelen, Old High German intsigilan. Related: Unsealed (late 14c.).
unscathed
unschooled
unscramble
unscriptural
unscrupulous
unseal
unsearchable
unseasonable
unseasoned
unseat
unsecure
