1. 飞行员
A flyer is a pilot of an aircraft.

2. 飞机乘客
You can refer to someone who travels by aeroplane as a flyer .

3. (广告)传单
A flyer is a small printed notice which is used to advertise a particular company, service, or event.

1. an advertisement (usually printed on a page or in a leaflet) intended for wide distribution

e.g. he mailed the circular to all subscribers

Synonym: circularhandbillbillbroadsidebroadsheetflierthrowaway

2. someone who operates an aircraft

Synonym: aviatoraeronautairmanflier

3. someone who travels by air

Synonym: flier