AMV stands for "Anime Music Video". Use this tag for questions you have about AMVs you've seen. Do not use this tag for questions about how to create AMVs.
An AMV ("Anime Music Video"; also "MAD", for "Music Anime Douga") is a video that uses short clips from one or more anime series and montages them to a soundtrack. Usually, this term is used to refer to unofficial (and often amateur) fan-made videos. For example: "Animegraphy 2013".
This tag should be used for questions about AMVs that you've seen. Questions about how to make AMVs are not on-topic here, but may be on-topic at Video Production.
For more information:
- Anime music video at Wikipedia