1. With firmness
   "'I will come along,' she said decisively"
   - resolutely 
2. With finality; conclusively
   "the voted settled the argument decisively" 
3. In an indisputable degree
   "the Fisher Act of 1918 decisively raised their status and pay"

See also: decisive

Antonym: indecisively

• hors d'oeuvre
• hors de combat
• horse
• horse around
• horse balm
• horse barn
• horse blanket
• horse botfly
• horse breeding
• horse brier
• horse cassia
• horse cavalry
• horse chestnut
• horse doctor
• horse fancier
• horse gentian
• horse grain
• horse gram
• horse latitude
• horse mackerel
• horse manure
• horse mushroom
• horse nettle
• horse of the wood
• horse opera