'first', or other ordinal derivatives of 'one', such as hundred-and-oneth or minus-oneth
Used at the end of algebraic expressions indicating ordinal position that end in 1, such as (k+1)ᵗʰ
A fractional part of an integer ending in one
An ordinal value that is represented by an expression ending in 1 such as the (n + 1)th.
best, A-one, superior.