Breastheaght or Breastheight: How To spell?

The word Breastheaght is misspelled against Breastheight, a noun meaning "The interior slope of a fortification, against which the garrison lean in firing."

Word contains consecutive vowels 'EI' in between alphabets breasth & ght is misspelled as 'EA'
Wrong Spelling:  breasth-ea-ght 
Correct Spelling:  breasth-ei-ght 
Explore spell check of Breastheight to spell without errors.