apertive (n.)

"medicine capable of opening or dilating" (pores, bowels, etc.), "a laxative," early 15c., also as an adjective, from Latin aperitivus, from aperire "to open, uncover," from PIE compound *ap-wer-yo- from *ap- "off, away" (see apo-) + root *wer- (4) "to cover." Also aperient (1620s).