Latin word invictus comes from Latin victus, Latin ingratus (Thankless. Ungrateful. Unpleasant, disagreeable.)
victus (Latin)
Living, way of life. Nourishment, provision, diet, that which sustains life.
ingratus (Latin)
Thankless. Ungrateful. Unpleasant, disagreeable.
invictus (Latin)
Invincible, undisputed, undefeated. Unconquered, unsubdued.