Buldog or Bulldog: How To spell?

The word Buldog is misspelled against Bulldog, a noun meaning "A refractory material used as a furnace lining, obtained by calcining the cinder or slag from the puddling furnace of a rolling mill."

Bulldog has double "ll" is mispronounced as "l"
Remember double 'LL' in between the strings bu & dog which should not be misspelled with single 'L'
Wrong Spelling:  bu-l-dog 
Correct Spelling:  bu-ll-dog 
Check more misspelled words of Bulldog to spell it correct.