Sibilance is the sound someone makes when saying words that make the tongue push air through the front of the teeth, such as "zip" "jeep" "ship" and "chip". It can also refer to the non-word sounds that someone would make when getting someone's attention ("Ssst!") or telling one to be quiet ("shhhh!").
An acronym that stands for Sucess Is Built In The Summer. This acronym is typically used by sprinter in their off season long runs especially with their coach (eg. Kososki or Boz). This acronym originated in the Western Suburbs of Chicago.