What is art?

My previous art professor had a very good definition for it, IMO it's a great place to start interpreting your own feelings/implications about art. It was: "Art is the synthesis of techniques, many or few, to create a meaningful whole that is aesthetically, emotionally, or entertainingly pleasing for the spectator".

It's my go to definition for the topic, mainly because it's so encompassing of all art forms, even things like video games. It still leaves a lot of room for subjective interpretation as well.