1. Being a matter of form only; lacking substance
   "a form-only requirement that is usually ignored"

See also: formal

• sissiness
• sissoo
• sissu
• sissy
• sissyish
• sister
• sister-in-law
• sisterhood
• sisterlike
• sisterly
• sistership
• Sistine
• Sistine Chapel
• sistrum
• Sistrurus
• Sistrurus catenatus
• Sistrurus miliaris
• Siswati
• Sisymbrium barbarea
• Sisymbrium officinale
• Sisymbrium tanacetifolia
• Sisyphean
• Sisyphus
• Sisyridae
• Sisyrinchium