Um

Um may refer to:

• Um, an exclamation or filled pause in spoken conversation
• Um (Korean name)
• .um, the Top Level Domain for United States Minor Outlying Islands
• um for micrometre, sometimes written instead of the proper symbol µm in a limited character set
• -um-, an infix in many Austronesian languages
• Um interface, the air interface for the GSM mobile telephone standard

UM may refer to:

• Utilization management, is the evaluation of the appropriateness, medical need and efficiency of health care.
• UM (company), an advertising agency formerly known as Universal McCann
• Air Zimbabwe, IATA code UM
• United Methodist
• Unified Messaging
• The Union for the Mediterranean
• United States Minor Outlying Islands, ISO 3166 code UM
• Umphrey's McGee, a jam band
• Unified Model, a global numerical weather prediction model