1. the process of making something formal or official; the act of giving something a formal structure or status
Usage: British English spelling; American English uses 'formalization'; commonly used in academic, legal, and organizational contexts
2. in logic and mathematics, the process of expressing ideas, rules, or systems in a precise, symbolic, or axiomatic form
Usage: technical; used in formal logic, mathematics, and computer science

Examples

• The formalisation of the company's dress code was announced in the employee handbook.
• The agreement required formalisation through a written contract signed by both parties.
• Formalisation of the new procedures helped ensure consistency across all departments.
• The formalisation of their relationship came when they decided to get married.
• In mathematics, the formalisation of geometry relies on precise definitions and axioms.
• The formalisation of the rules made the game easier to understand and play fairly.