Thrumed or Thrummed: How To spell?
The word Thrumed is misspelled against Thrummed, which is past tense of "Thrum"
Thrummed has double "mm" is mispronounced as "m"Remember double 'MM' in between the strings thru & ed which should not be misspelled with single 'M'
Wrong Spelling:  thru-m-ed  Correct Spelling:  thru-mm-ed 
Check more misspelled words of Thrummed to spell it correct.