1) Brief interjections 2) Conversation fillers 3) Conversational fillers 4) Er relatives 5) Faltering sounds 6) Fluent speakers avoid them 7) Followers of wells 8) Hesitant sounds 9) Kin of hems and haws 10) Sentence interrupters 11) Sounds of hesitation 12) Sounds of indecision 13) Speech interruptions 
Unified messaging service. The concept of bringing together all forms of messaging in a single service. Component services potentially including fax messaging, VMS (voice), SMS (text), MMS (multimedia) and email.
User Mode Scheduler
Upper Main Sequence, used to describe the more massive hydrogen-burning main sequence stars