Short nose or from the court
A modern spelling variation of the French surname Courtney. It likely originated from a nickname for someone with a 'short nose' (curt nez) or as a locational name referring to the court of a nobleman.
Less common today
Courtnei isn't in the latest US Top 1000. It last peaked at #4,850 in 1990.
US births per 5-year period, 1990βpresent (SSA data).