Formation of small tangles of fibers when the surface of a material is rubbed against itself or another surface. Looks like small fabric balls on the fabric surface. The tendency to pill is not a desirable quality in a fabric. Found on http://www.encyclo.co.uk/local/21117
A condition, often caused by heavy use, in which fibers from different tufts of carpet become entangled in one another forming hard fiber masses or `pills`. These pills can be cut off with scissors. Found on https://www.encyclo.co.uk/local/22737