Common legal phrase. Lawful action, such as an agreement consciously agreed to by two or more entities, establishing lawful accountability. For example, an apartment lease legally binds the lessor and the lessee. An illegal action, such as forcing, tricking, or coercing a person into an agreement, is not legally binding. The document's signing gives the number of conditions the weight of law. Both parties knowingly understand what they are agreeing to is the other requirement to legally establish an agreement or contract.
TLD Example: The judge agreed believed the evidence showed the contract with the buyer to be legally binding and awarded the seller damages for breach of contract.