What is a very commonly used object that's name is unknown to most of the population?

1. Sphygmomanometer = Blood Pressure Cuff
   — AudibleNod


2. The small pocket in a pair of pants is called a watch pocket.
   — alltherobots


3. You know those grey plastic theft detection things in the doorways of most stores? No idea what those are called.
   — TwoLastNamesGuy






4. Church Key or churchkey - the little dohickey you use to open a bottle on one side and make an opening in a can with the other.
   — SuperdudeAbides


5. Peen - side opposite of the hammers striking side
   — Suburbanslim


6. The little valve at the bottom of a motorcycle gas tank is called a petcock. So many people call it "the fuel shutoff."
   — Skunk73






7. That metal thing you measure your feet in is a Brannock Device.
   — crystalistwo


8. The weird 4 pronged trident looking thing I use to stab my food and eat with it.
   — anooblol


9. The cage-thing that secures the cork on a bottle of champagne is called "muselet".
   — HabseligkeitDerLiebe






10. A fastening (typically found on coats) where a loop fastens around a button is called a 'frog'.
    — Clypsedra


11. The dot over a lowercase j and i is called a tittle.
    — SalemScout