hiddenclasp
nounUK /ˈhɪdən klɑːsp/
US /ˈhɪdən klæsp/
A hidden clasp is a small lock you cannot see that keeps something closed.
The necklace has a hiddenclasp so it looks like one smooth piece of gold.
OTHER MEANINGS
2. A secret way of holding two things together that is not easy to notice.
The box opened only when you pressed the hiddenclasp on its side.
3. A quiet or sneaky grip or hold.
He kept a hiddenclasp on the rope so no one would see him holding it.
4. A small hidden part on a book or bag that keeps it shut.
The old diary had a hiddenclasp under its leather cover.