What is the meaning of lag?

noun

• The act of slowing down or falling behind.
  • synonyms: slowdown, retardation
• The time between one event, process, or period and another.
  • usage: "meanwhile the socialists are running the government"
  • synonyms: interim, meantime, meanwhile
• One of several thin slats of wood forming the sides of a barrel or bucket.
  • synonyms: stave

verb

• Hang (back) or fall (behind. in movement, progress, development, etc.)
  • synonyms: dawdle, fall back, fall behind
• Lock up or confine, in or as in a jail.
  • usage: "The suspects were imprisoned without trial"; "the murderer was incarcerated for the rest of his life"
  • synonyms: imprison, incarcerate, immure, put behind bars, jail, jug, gaol, put away, remand
• Throw or pitch at a mark, as with coins.
• Cover with lagging to prevent heat loss.
  • usage: "lag pipes"