Skywriting (noun)

1. The art or technique of writing messages in the sky using smoke trails produced by an aircraft.
2. An advertising message or image written in the sky using smoke or other materials.

Origin:

From the phrase "writing in the sky".

Examples:

1. The skywriting at the event spelled out the company's name.
2. I saw a beautiful skywriting of a heart in the sky.
3. The skywriting was a surprise for the couple's anniversary.
4. The pilot was an expert in skywriting and had written messages for many years.
5. The skywriting was a way for the company to grab attention in an unconventional way.