real definition of likert scale?

It depends on the specific likert scale, but generally it is the ordinal level

Can a 3-point scale also be called a Likert scale?? PS

The Likert type question is used to determine the respondent attitude or feeling on a particular specific item. There are numerous ways to set up the answer types on the Likert scale; see the related links.

A Likert scale is considered a quantitative measurement tool because it assigns numerical values to responses and allows for numerical analysis of data.