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

See also: epidemic, noxious, pestilence

• order Zygnemales
• order Zygnematales
• order-Chenopodiales
• ordered
• ordered series
• orderer
• ordering
• orderliness
• orderly
• orderly sergeant
• ordinal
• ordinal number
• ordinance
• ordinand
• ordinarily
• ordinariness
• ordinary
• ordinary annuity
• ordinary bicycle
• ordinary care
• ordinary life insurance
• ordinary seaman
• ordinary shares
• ordinate
• ordination