According to the Blue Letter Bible website is found in the New Testament twenty-seven times. Twenty-two of those times, the bulk of its usage are in the book of Revelation. It is primarily used as a noun in the book of Revelation. The other non-Revelation usages, twice in the gospels and three times in Pauline letters, are used as a verb. In Greek “σφραγίζω” is transliterated as sphragizō. Phonetically, if attempted to pronounce “sfrä-gē'-zō” or “sa frogs o” would get the closest.
The origin of the word is Babylonian and that it may have originally the word sphragís that occurs in Ex. 35:22 is the word for “bracelet.” As this verb has evolved, seal has developed both a figurative and literal sense. The word seal that is found in this passage is the same word for seal was used to describe the sealing of the tomb for Jesus (i.e. Mat27:66) and sealing of the pit that Satan falls into