An indexable cutting insert comprising: opposing upper and lower surfaces (42, 44) and an insert peripheral surface therebetween and an insert axis extending therethrough, the lower surface having a bearing surface and first and second lower abutment surfaces (52a, 52b) transverse thereto, and the insert peripheral surface having opposing first and second insert end surfaces (54a, 54b) spaced apart by opposing first and second insert side surfaces (56a, 56b), with first and second cutting edges (58a, 58b) formed at the intersection of the upper surface and the first and second insert end surfaces (54a, 54b), respectively, characterized in that: in a cross-section taken in a horizontal plane perpendicular to the insert axis and intersecting the insert peripheral surface: first and second peripheral corner points (NC1, NC2) formed at the intersection of the first insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a first lateral side of an imaginary acute trapezoid, third and fourth peripheral corner points (NC3, NC4) formed at the intersection of the second insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a second lateral side of the imaginary acute trapezoid, and the first and third peripheral corner points (NC1, NC3) define the end points of a short base of the acute trapezoid, and the second and fourth peripheral corner points (NC2, NC4) define the end points of a long base of the acute trapezoid, and in a bottom view of the cutting insert: the first and second lower abutment surfaces (52a, 52b) form an obtuse first tilt angle (α1) and are located inside the imaginary acute trapezoid. opposing upper and lower surfaces (42, 44) and an insert peripheral surface therebetween and an insert axis extending therethrough, the lower surface having a bearing surface and first and second lower abutment surfaces (52a, 52b) transverse thereto, and the insert peripheral surface having opposing first and second insert end surfaces (54a, 54b) spaced apart by opposing first and second insert side surfaces (56a, 56b), with first and second cutting edges (58a, 58b) formed at the intersection of the upper surface and the first and second insert end surfaces (54a, 54b), respectively, the lower surface having a bearing surface and first and second lower abutment surfaces (52a, 52b) transverse thereto, and the insert peripheral surface having opposing first and second insert end surfaces (54a, 54b) spaced apart by opposing first and second insert side surfaces (56a, 56b), with first and second cutting edges (58a, 58b) formed at the intersection of the upper surface and the first and second insert end surfaces (54a, 54b), respectively, characterized in that: in a cross-section taken in a horizontal plane perpendicular to the insert axis and intersecting the insert peripheral surface: first and second peripheral corner points (NC1, NC2) formed at the intersection of the first insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a first lateral side of an imaginary acute trapezoid, third and fourth peripheral corner points (NC3, NC4) formed at the intersection of the second insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a second lateral side of the imaginary acute trapezoid, and the first and third peripheral corner points (NC1, NC3) define the end points of a short base of the acute trapezoid, and the second and fourth peripheral corner points (NC2, NC4) define the end points of a long base of the acute trapezoid, and in a bottom view of the cutting insert: the first and second lower abutment surfaces (52a, 52b) form an obtuse first tilt angle (α1) and are located inside the imaginary acute trapezoid. first and second peripheral corner points (NC1, NC2) formed at the intersection of the first insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a first lateral side of an imaginary acute trapezoid, third and fourth peripheral corner points (NC3, NC4) formed at the intersection of the second insert end surface and the first and second insert side surfaces (56a, 56b), respectively, define the end points of a second lateral side of the imaginary acute trapezoid, and the first and third peripheral corner points (NC1, NC3) define the end points of a short base of the acute trapezoid, and the second and fourth peripheral corner points (NC2, NC4) define the end points of a long base of the acute trapezoid, and in a bottom view of the cutting insert: the first and second lower abutment surfaces (52a, 52b) form an obtuse first tilt angle (α1) and are located inside the imaginary acute trapezoid.