Duhaime's Law Dictionary Condition Subsequent Definition: A condition in a contract that causes the contract to become invalid if a certain event occurs. A condition in a contract or will that causes the contract to become invalid if a certain event occurs. This is different from a condition precedent. The happening of a condition subsequent may invalidate a contract which is, until that moment, fully valid and binding. In the case of a condition precedent, no binding contract exists until the condition occurs. REFERENCES: Re McColgan Estate, 1969 DLR 572 Categories & Topics: Duhaime's Contract Law Dictionary Always looking up definitions? Save time with our search provider (modern browsers only) If you find an error or omission in Duhaime's Law Dictionary, or if you have suggestion for a legal term, we'd love to hear from you!