Si s - spar
- sine vi aut dolo
- sinecure
- single
- single adultery
- single bill
- single bond
- single combat
- single creditor
- single dwelling house
- single dwelling restriction
- single family
- single letter
- single man
- single original
- single premium annuity contract
- single publication rule
- single shot
- single subject
- single tax
- single tax club
- single woman
- single-member district
- single-story dwelling
- singular
- singulariter
- Singuli in solidum tenentur
- sink
- sinking fund
- sinking fund tax
- sirup
- sister
- sister state
- sister-in-law
- sit
- sit in banc
- sit in bank
- sit in camera
- sit in misericordia
- Sit quilibet homo dignus venatione sua, in silva, et in agris, sibi propriis, et in dominio suo; et abstineat omnis homo a venariis regiis, ubicunque pacem eis habere voluerit
- sit-down strike