This paper presents a generalization of the concepts of partial--isometry and left polynomially partial isometry. Our investigation is inspired by previous work in the field [5, 30, 31]. By extending the definition of partial--isometry, we provide new insights into the properties and applications of these mathematical objects. In particular, we define the notion of left -partial--isometry as a broader class of operators, including partial--isometry and left polynomially partial isometry. Some basic properties of a left -partial--isometry are proven, as well as its relation with -isometry. Several decompositions of a left -partial--isometry are developed. We consider spectral properties and matrix representation of left -partial--isometries. Additionally, we provide some applications of left -partial--isometries.