despatch, dispatch, expedition, expeditiousness, fleetness, immediacy, immediateness, instancy, promptitude, promptness.
spikenards, sandpipers, dispersant, dispensary.
Your query has returned 529 words, which include anagrams of rapidness as well as other shorter words that can be made using the letters included in rapidness.
The words in this list can be used in games such as Scrabble, Words with Friends, Wordscapes and other similar games.