Words Ending in IX: The Latin Suffix Still Going Strong
The -IX ending is a Latin fingerprint on English vocabulary. MATRIX, APPENDIX, PHOENIX, PREFIX, SUFFIX — these words retain their Latin -IX ending rather than adopting an English suffix. Many -IX words also keep their Latin plural form: one MATRIX becomes multiple MATRICES, one APPENDIX becomes APPENDICES. This dual-plural situation (APPENDIXES is also valid) makes -IX words a reliable source of crossword clues and occasional spelling debates. In word games, the X at the end is the real prize — X scores 8 points in Scrabble, and placing it on a premium square while completing an -IX word can produce enormous scores.
MIX and FIX are the workhorses of this family. Short, common, and endlessly extendable — MIXING, MIXER, MIXTURE, ADMIX, INTERMIX, REMIX. SIX carries the bonus of being a number word, which crossword constructors lean on constantly. AFFIX (10 points) is a crossword favorite clued as "attach" or "stamp." For more obscure entries, CERVIX (medical anatomy), HELIX (spiral structure), and ONYX-adjacent words fill harder puzzle grids. The three-letter options — FIX, MIX, SIX, NIX, PIX — are Scrabble essentials because they drop X on the board while using minimal tiles.
Scoring tip: if an X is already on the board, look for ways to build -IX words by placing tiles before it. Turning a lonely X into MIX, FIX, or SIX costs just two tiles and scores at least 10 points. For the other high-value letter endings, check words ending in AX and words ending in X for the full picture. Browse words starting with A for AFFIX, ADMIX, and other A-opening -IX combos.
FAQ
Do -IX words use -ICES or -IXES for plurals?
Both forms are usually accepted. APPENDIXES and APPENDICES are both valid in dictionaries and in Scrabble. The -ICES form follows Latin grammar, while -IXES follows English rules. In crosswords, constructors tend to prefer -ICES because the alternating vowels create better letter crossings. For other Latin plural patterns, see words ending in Y, where -Y becomes -IES.
What -IX words score highest in Scrabble?
COMMIX (19 points base) and OUTFOX-adjacent words aside, CERVIX at 18 points and PROLIX at 15 points are strong plays. The real scoring comes from X landing on premium squares — a triple letter score under the X in MIX turns 12 points into 28. For other X-placement strategies, see words ending in X and words starting with X.
Why does PHOENIX end in IX if it's Greek?
PHOENIX came to English through Latin, which adapted the Greek PHOINIX. Latin kept the -IX ending, and English inherited the Latin spelling. The word originally referred to the mythical bird that burns and is reborn. Many Greek words reached English via Latin detours, picking up Latin spellings along the way. For more Greek-via-Latin words, explore words starting with PH.