LIGHTFAST Synonyms There is 1 synonym of the word lightfast. (exact relations) There is 0 hypernym of the word lightfast. (close relations)Did you mean?Definition of LIGHTFASTAlso try synonyms for..lightlightslightedlighterlightensBest Alternative Words for LIGHTFASTTop 20Top 10 Top 20 (Default)Top 50 Top 100 All All (Default)WordsPhrases All All (Default)Verb Noun Adjective Adverb RankWordSave?More Syns..UsageType1colorfastadjectiveadj Alternatives for COLORFAST Words (2)permanentunfadingAll synonyms for colorfast