1. A soft mass, especially of some loose, fibrous substance, used for various purposes.
2. A little mass, tuft, or bundle, as of hay.
3. (Archaic) A little mass of some soft or flexible material, such as hay, paper, or old rope yarn, used for retaining a charge of powder in a gun.

1 To insert a wad into
2. To form into a wad or wadding; especially; to roll or crush into a tight wad
3. To stuff or line with some soft substance