Ingratitude is a failure to show thanks for kindness. Base ingratitude, sheer ingratitude, met with ingratitude.
It is a heavier charge than rudeness, because it says a debt was owed and ignored — which is why it appears in Shakespeare and in family arguments. It is formal. Note gratitude, grateful, grace, all from the Latin gratus, meaning pleasing or thankful.
1nouningratitudeA failure to show thanks for kindness.
“After all we did for him, his ingratitude really hurt.”
ingratitude is a failure of thanks.
Latin ingratitudo is in- plus gratus, thankful or pleasing. Grace, grateful and gratis come from the same pleasing.
Latin
ingrātitūdō
Old French
ingratitude
English, today
ingratitude
From in- + gratitude, from Old French ingratitude, from Latin ingrātitūdō. by surface analysis, in- + grat(us) + -itude.
Etymology from Wiktionary, CC BY-SA