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

See also: epidemic, noxious, pestilence

• Salix pendulina blanda
• Salix pentandra
• Salix purpurea
• Salix pyrifolia
• Salix repens
• Salix sericea
• Salix sitchensis
• Salix triandra
• Salix tristis
• Salix uva-ursi
• Salix viminalis
• Salix vitellina
• Salk
• Salk vaccine
• sallet
• sallow
• sallowish
• sallowness
• sally
• sally forth
• Sally Lunn
• sally out
• sallying forth
• Salmacis
• salmagundi