Strong's Greek: 4972. σφραγίζω (sphragizó) -- to seal
biblehub.com › greek › 49724972 sphragízō (from 4973 /sphragís, "a seal") – properly, to seal (affix) with a signet ring or other instrument to stamp (a roller or seal), i.e. to attest ownership, authorizing ( validating) what is sealed. 4972 /sphragízō ("to seal") signifies ownership and the full security carried by the backing (full authority) of the owner.