1. Exceedingly harmful
   - baneful, deadly, pernicious 
2. Likely to spread and cause an epidemic disease
   - pestilential, pestiferous, plaguey

See also: epidemic, noxious, pestilence

• protectiveness
• protector
• outstation
• outstay
• outstretch
• outstretched
• outstrip
• outstroke
• outswinger
• outtake
• outthrust
• outturn
• outvie
• outvote
• outwait
• outward
• outward-bound
• outward-developing
• outward-moving
• outwardly
• outwardness
• outwards
• outwear
• outweigh
• outweird