Used after a pause for thought to introduce a new topic, question or story, or a new thought or question in continuation of an existing topic.

(music) A syllable used in solfège to represent the fifth note of a major scale.

Reduced form of 'so that', used to express purpose; in order that. / With the result that; for that reason; therefore. / Used to connect previous conversation or events to the following question.

To the (explicitly stated) extent that. / (informal) Very (positive clause). / (informal) Very (negative clause). / (slang, chiefly US) Very much. / In a particular manner.

A Mon-Khmer-speaking people of Laos and Thailand.

A Chinese surname from Cantonese.

Roughly, approximately.

The conventional Morse code call made by a ship in distress.

(games) A children's game in which players take turns to place S's and O's on a grid, collecting points by creating an "SOS" sequence.

(idiomatic, childish) A defiant expression used to finish a poorly-made argument.