Bilethead or Billethead: How To spell?
The word Bilethead is misspelled against Billethead, a noun meaning "A round piece of timber at the bow or stern of a whaleboat, around which the harpoon lone is run out when the whale darts off."
Billethead has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings bi & ethead which should not be misspelled with single 'L'
Wrong Spelling:  bi-l-ethead  Correct Spelling:  bi-ll-ethead 
Find more wrongly spelled words of Billethead to spell it well.