filler

n. 1. One who, or that which, fills; something used for filling. [ 1913 Webster ]

'T is mere filler, to stop a vacancy in the hexameter. Dryden. [ 1913 Webster ]

They have six diggers to four fillers, so as to keep the fillers always at work. Mortimer. [ 1913 Webster ]

2. (Paint.) A composition, as of powdered silica and oil, used to fill the pores and grain of wood before applying paint, varnish, etc. [ Webster 1913 Suppl. ]

3. (Forestry) Any standing tree or standard higher than the surrounding coppice in the form of forest known as coppice under standards. Chiefly used in the pl. [ Webster 1913 Suppl. ]