pikraino describes making the stomach or waters bitter and, in a marital warning, becoming embittered toward a wife.

Its dominant attested use concerns something becoming bitter in the stomach or in waters; a separate interpersonal use warns husbands against becoming embittered toward their wives.

1. Becoming bitter in stomach or waters · dominant

   In Revelation 10:9, the future active form occurs in the angel's statement that the little scroll will make the stomach bitter; Revelation 10:10 reports the result after it is eaten with an aorist passive singular form. In Revelation 8:11, an aorist passive plural form occurs in the clause about waters that had been made bitter, followed by deaths from those waters.

   Revelation 10:9Revelation 10:10Revelation 8:11
2. Becoming embittered toward a wife · occasional

   In Colossians 3:19, the present passive plural form occurs in the instruction to husbands alongside loving their wives; the APB renders the following prohibition, "do not be embittered toward them."

   Colossians 3:19

In the Anselm Project Bible: The APB presents the physical clauses with "make your stomach bitter," "was made bitter," and waters that "had been made bitter," while Colossians 3:19 has "be embittered toward them." These are whole-verse translation renderings rather than definitions.