Intervalum or Intervallum: How To spell?
The word Intervalum is misspelled against Intervallum, a noun meaning "An interval."
Intervallum has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings interva & um which should not be misspelled with single 'L'
Wrong Spelling:  interva-l-um  Correct Spelling:  interva-ll-um 
Check more misspelled words of Intervallum to spell it correct.