- Of the fifth degree.
- An algebraic function of the fifth degree.
- Of the fifth degree or order.
- Of or relating to the <xref>fifth</xref> <xref>degree</xref>, such as a quintic <xref>polynomial</xref> which has the form ax5+bx4+cx3+dx2+ex+f (containing a term with the independent variable raised to the fifth power).
- a quintic <xref>polynomial</xref>: ax5+bx4+cx3+dx2+ex+f