1. Without warning or announcement
   - unannounced, unheralded

See also: unexpected

• scalar
• scalar field
• scalar matrix
• scalar product
• scalariform
• scalawag
• scald
• scalded milk
• scale
• scale down
• scale factor
• scale fern
• scale insect
• scale leaf
• scale moss
• scale of C major
• scale of measurement
• scale up
• scale value
• scale wax
• scaled
• scaleless
• scalelike
• scalene
• scalene muscle