[in.fest] vt [F infester, fr. L infestare, fr. infestus hostile] (1602) 1: to spread or swarm in or over in a troublesome manner "a slum ~ed with crime" "shark-infested waters"
2: to live in or on as a parasite -- in.fes.tant n -- in.fes.ta.tion n -- in.fest.er n