1. Not mated sexually 
2. Of someone who has no marriage partner

See also: single, unmarried, unmated

• genus Swietinia
• genus Sylvilagus
• genus Symphalangus
• genus Symphoricarpos
• genus Symphytum
• genus Symplocarpus
• genus Symplocus
• genus Synagrops
• genus Synanceja
• genus Synaptomys
• genus Synchytrium
• genus Synercus
• genus Syngnathus
• genus Syngonium
• genus Syringa
• genus Syrrhaptes
• genus Syzygium
• genus Tabernaemontana
• genus Tacca
• genus Tachyglossus
• genus Tachypleus
• genus Tadarida
• genus Tadorna
• genus Taenia
• genus Tagetes