A constitution is said to be rigid if it has cumbersome provision for its amendment. A rigid constitution is one that is difficult to amend or change. This may be because the constitution contains complex or stringent amendment procedures, such as requiring a supermajority or multi-stage ratification process, which make it difficult to alter the constitution's provisions. Rigid constitutions are often contrasted with flexible or elastic constitutions, which can be more easily amended or changed. The rigidity or flexibility of a constitution can have significant implications for a country's political system and its ability to adapt to changing circumstances over time.
It is important to note that a rigid constitution is not one that can only be interpreted by the military, nor is it a result of difficult authors. Additionally, the power to amend a constitution is not solely the prerogative of the executive, but is often a shared responsibility of the different branches of government or the people themselves.