Definitions for jaggiesˈdʒæg iz
Random House Webster's College Dictionary
a jagged, stairstep effect on curved or diagonal lines that are reproduced in low resolution, as on a printout or computer display.
Origin of jaggies:
Jagged artifacts in raster graphics, such as those caused by resizing a bitmap image without preserving its aspect ratio.
Origin: jaggy or jagged with diminutive -ie and plural -s.
The New Hacker's Dictionary
The ‘stairstep’ effect observable when an edge (esp. a linear edge of very shallow or steep slope) is rendered on a pixel device (as opposed to a vector display).