Part of speech: Noun
a rate that is rapid
Part of speech: Noun
intelligence as revealed by an ability to give correct responses without delay
Part of speech: Noun
skillful performance or ability without difficulty
Example: his quick adeptness was a product of good design; he was famous for his facility as an archer
Mental quickness, Rapidness, Deftness, Quickness, Rapidity
The word "quickness" comes from Middle English quiknes.
quick – A related word in the same word family.
ness – A related word in the same word family.
The printing press standardized Middle English spelling, freezing many irregular forms we use today.