To Exonerate

1. (transitive, now rare) To relieve (someone or something) of a load; to unburden (a load).
2. (obsolete, reflexive) Of a body of water: to discharge or empty (itself).
3. (transitive) To free from an obligation, responsibility or task.
4. (transitive) To free from accusation or blame.

Synonyms: acquit, exculpate