LSJ
ὁ, creation of a mouth-filling word, as ἀμφασία, γνάμπτω for ἀφασία, γνάπτω, Eust. 1123.41, 1350.24.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ὁ, das Großreden, Prahlen, Nicet.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)