innocence: the state of being clean of guilt, with nothing on you that anyone can hold against you (and once, plainly, cleanness itself)
This is the noun for a quality that Hebrew describes as cleanness. It belongs to a small family built on a verb that means to be clean, empty, or free of a claim (נָקָה), and where the adjective of that family names the person who is in the clear (נָקִי), this word names the condition itself. The condition is a negative one in the best sense: there is nothing on you, nothing sticking to you, nothing that could be brought against you.
Four of its five appearances are about guilt, and three of those four use the same image: hands. Abimelech protests that he took Sarah with a whole heart and clean hands (Genesis 20:5). The worshipper of Psalm 26:6 washes his hands in innocence before walking around the altar, and the worshipper of Psalm 73:13 asks bitterly whether he has kept them clean for nothing. Hands are where a deed shows, so hands are where innocence is claimed, and the gesture outlived the Hebrew Bible: Pilate washes his hands before a crowd and calls himself innocent (ἀθῷος) of the man's blood (Matthew 27:24).
Hosea 8:5 pushes the same idea in a different direction. There innocence is not a claim someone makes but a state a whole nation cannot reach, something the people are simply unable to arrive at while the calf of Samaria still stands.
The last appearance turns the word back to its plainest sense. In Amos 4:6 God says he gave Israel cleanness of teeth, and the next line explains what he means: a lack of bread. Teeth stay clean when there is nothing to eat. It is the bleakest kind of joke, and it is the clearest proof that behind the moral word there was always the simple picture of being empty.