LAGGING

verb

1. To fail to keep up (the pace), to fall behind
2. To cover (for example, pipes) with felt strips or similar material (referring to a time lag effect in thermal transfer)
3. To transport as a punishment for crime.

noun

1. The covering of something with strips of felt, wood etc, either as insulation or for protection.
2. The material so used.
3. A prison sentence.

adjective

1. Falling behind, not keeping up the pace
2. Occurring after; indicating the later phase of