1. Used of syllables
   - atonic 
2. (used of vowels or syllables) pronounced with little or no stress
   - light, weak

See also: unstressed

• plotter
• plough
• plough horse
• umbel
• umbel-like
• Umbellales
• umbellar
• umbellate
• umbellifer
• Umbelliferae
• umbelliferous
• umbelliferous plant
• umbelliform
• Umbellularia
• Umbellularia californica
• umber
• umbilical
• umbilical cord
• umbilical hernia
• umbilical vein
• umbilical vesicle
• umbilicate
• umbilicus
• umbles
• umbo