What does Gu stand for?

Guillelmus de Tocco - Authority cited in pre-1607 legal work (DSA)

geographically unsuitable (SAUS)

Guam - MARC country of publication code - Library of Congress (LCCP)

Aviateca - ICAO designator (AD)

Gasschutzunteroffizier - Gas Noncommissioned Officer - German military - World War II

Gastric Ulcer - Medicine

Gear Up - Aviation

Geek Undecided (SAUO)

General Reserve Unit (SAUO)

Generations United (EA)

Generic (SAUS)

Generic Unit (TEL)

Genitourinary - Medicine

Geographically Undesirable - Slang

Georgetown University - Washington, DC

Get Unique (SAUS)

Giant Urticaria - Medicine (MELL)

Gifu University (SAUO)

Glasgow University (SAUO)

Glucose Uptake - Medicine (MELL)

Glucuronidase (SAUS)

Glycogenic Unit - Medicine

Gonococcal Urethritis - Medicine

Gonzaga University (SAUO)

Government Unit (SAUO)

Grafton & Upton Railroad Co. - AAR code

Gramophone Unit (SAUS)

Grand United Friendly Society - Australia

Gravitational Ulcer - Medicine

Greater Union Organisation - Australia

Group Unit (SAUO)

Guam - Postal code - ANSI two-letter standard code (CNC)

Guanajuato - NCIC Mexican state code (NCIC)

Guanase - An enzyme

Guanethidine - Medicine (EDAA)

Guarantee

Guard - Telegraphy (PCTE)

Guatemala - IYRU nationality code (IYR)

Guidance Unit

Guinea

Gules - Heraldry

Gunner (ADA)

Gutman Unit - Medicine (EDAA)

University of Georgia (SAUO)

University of Georgia, Athens, GA - Library symbol - Library of Congress (LCLS)