Incorrect spelling

seniour

Incorrect spelling, explanation: this form is incorrect. The word senior comes directly from Latin word of the exact same spelling, therefore senior is the correct spelling. Seniour is mistaken, maybe due to different American and British spellings of -our/-or words (behavior vs behaviour etc.).


Correct spelling

senior

Correct spelling, explanation: senior is Latin loanword (older); it hasn’t been change in any way in English. It is a comparative form of the adjective senex, meaning old. Senior is therefore the correct form, while seniour is a misspelling made probably due to British spelling of such words as colour or flavour.

Definition of senior:
adjective, older, of higher position
Jessica is a senior accountant in our company.
noun, someone older than someone else, especially in a family; in school: student in their final year
Frederick will be a senior next school year.


Incorrect spelling

seinor

Incorrect spelling

Incorrect spelling

sennior

Incorrect spelling

Incorrect spelling

senoir

Incorrect spelling