2. Abbreviation. regular ¹
3. Abbreviation. regulation ¹
4. Abbreviation. registrar ¹
5. Abbreviation. registration ¹
6. Noun. (rare) A hard surface of rock fragments set in a sandy matrix, found in some hot deserts. ¹
¹ Source: wiktionary.com
Definition of Reg
1. a regulation [n -S] - See also: regulation