Clear means:

• In common usage, clear is a synonym for transparent.
• Clear (Scientology) is a state hypothesized by Dianetics and Scientology meaning a being who has removed all his engrams (bad memories).
• In financial terms, it refers to the process of making good on an obligation, such as transferring the funds from the writer of a cheque to the receivor of the cheque.
• To remove from current memory previous numbers or results in an adding machine.