noun

• (nautical) Clipping of submersible.
• (informal) Clipping of substitute, often in sports or teaching.
  "With the score 4 to 1, they brought in subs."
• (British, informal, often in plural) Clipping of subscription (“a payment made for membership of a club, etc.”).
  "According to the best available information, GALAXY has several times as many subs as any other science fiction magazine!"
• (Internet, informal) Clipping of subtitle
  "I've just noticed a mistake in the subs for this film."

verb

• (US, informal) To substitute for.
• (US, informal) To work as a substitute teacher, especially in primary and secondary education.
• (British, informal, soccer) To replace (a player) with a substitute.
  "He never really made a contribution to the match, so it was no surprise when he was subbed at half time."
• (British, informal, soccer, less common, often as "sub on") To bring on (a player) as a substitute.
  "He was subbed on half way through the second half, and scored within minutes."

verb

• (microscopy) To prepare (a slide) with a layer of transparent substance to support and/or fix the sample.
  "1997, Marina A. Lynch, S. M. O'Mara (editors), Ali D. Hames, D. Rickwood (series editors), Neuroscience Labfax, page 166, Ensure that gloves are worn when handling subbed slides. Although the following protocol describes subbing with gelatin, slides may also be coated with either 3-(triethoxysilyl-)propylamine (TESPA) or poly-L-lysine for in situ hybridization."