Incorrect spelling

seniour

Incorrect spelling, explanation: this form is incorrect. The word senior comes directly from a 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 a Latin loanword (older); it hasn’t been changed 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