From megas (great) and a root meaning to speak. To utter great or arrogant things, to speak boastfully. Often used of those who make grandiose claims without substance.
This word relates to the biblical warnings against arrogant speech. The 'little horn' in Daniel 'speaks great things' (Daniel 7:8, 20). The beast in Revelation has a mouth 'speaking great things and blasphemies' (Revelation 13:5). Arrogant speech is consistently associated with opposition to God. True greatness speaks humbly; false greatness advertises itself.