GMP

There are several expansions of the abbreviation GMP:

Airport code for Gimpo Airport in Seoul, South Korea
Good Manufacturing Practice, a guideline for manufacturers of medications (including pharmaceuticals, biotechnology products, and active pharmaceutical ingredients) to assure that medications are of the required quality. The term cGMP is uniquely used in the United States and refers to current Good Manufacturing Practice
GNU Multi-Precision Library, an arbitrary precision numerical calculation programming library
Guanosine monophosphate, a nucleotide
Guaranteed Minimum Pension under United Kingdom pensions legislation
Greater Manchester Police, Manchester, United Kingdom
There are some factories called "General Metal Products"
Guaranteed Maximum Price, a contract mechanism establishing a maximum cost for a given product or service.