fastness, firmness, fixedness, fixity, fixture, secureness, steadiness, tautness, tightness.
Your query has returned 1265 words, which include anagrams of immovablenesses as well as other shorter words that can be made using the letters included in immovablenesses.
The words in this list can be used in games such as Scrabble, Words with Friends, Wordscapes and other similar games.