Isochaum or Isocheim: How To spell?

The word Isochaum is misspelled against Isocheim, a noun meaning "A line connecting places on the earth having the same mean winter temperature. Cf. Isothere."

Word contains consecutive vowels 'EI' in between alphabets isoch & m is misspelled as 'AU'
Wrong Spelling:  isoch-au-m 
Correct Spelling:  isoch-ei-m 
Check more misspelled words of Isocheim to spell it correct.