Other forms: explained; explains; explaining
To explain something is to define it, show how it works, or just tell what it is. Explaining helps people understand.
If you know football really well, then you could probably explain it to a non-fan. Explaining makes things clearer. A lot of teaching is explaining — telling how something works. Also, if you do something wrong, people will ask you to explain your actions. Explaining can help someone "get it" — whatever "it" is.