precompact adjective 2verb 1forms 3 adjective2 •Forming a relatively compact subspace; Having a closure that is compact. •Totally bounded; Having a cover that consists of finitely many finite subsets. verb1 •To compact partially in preparation for full compaction or extrusion.The mixture finally moves to the compaction chamber where the auger motion precompacts the mixture to remove as much void space as possible prior to extrusion through a shaped die. — 1994 formsprecompacted · precompacting · precompacts