Strong's G4972 — σφραγίζω (verb)
sphragizo (sfrag-id'-zo) v.
1. to stamp (with a signet or private mark) for security or preservation
2. (by implication) to keep secret, to attest
{literally or figuratively}
[from G4973]
KJV: (set a, set to) seal up, stop 
Root(s): G4973 
Hebrew root: σφραγίς
Occurrences: 15