Incorrect spelling, explanation: we don’t spell this word coloumn since the right form column comes from Latin columnus. The mistake is probably made because of the British spelling of colour, however, this -our ending in British spelling is only for consonant r at the end. Because of this column is the correct spelling.

Correct spelling, explanation: column is the correct way to spell it because the word comes from Latin columnus. The misspelling coloumn is probably due to the rule of British English spelling of the -our ending (like in colour or favour). However, this only applies to ending with r so not for column.

Definition of column:
noun, in architecture a decorative pole to support the building; a formation of things or people
What a beautiful column! It must be very old.
The military column marching at the parade last week was really impressive!

Incorrect spelling

Incorrect spelling

Incorrect spelling