Correct spelling, explanation: the words flier and flyer have the same etymological origin and are considered variants of each other. The term ultimately comes from the Middle English word flien, meaning to fly. Over time, this evolved into the noun form fliȝere, which referred to a creature or thing that flies. Both flier and flyer have been used historically, and the choice between them is largely a matter of regional and individual preference. In contemporary English, both spellings are accepted.

Definition of flier:
1. Noun, a person, thing, or animal that travels by air
The majestic eagle, with its broad wingspan, is known to be a skilled and agile flier.
As the sun set over the horizon, a lone bat emerged from its roost, showcasing its abilities as a nocturnal flier.
2. Noun, a piece of paper containing an advertisement or information, usually given out to people walking by
The local band created a vibrant flier to announce its upcoming concert, featuring eye-catching graphics and details about the event.
The bookstore distributed fliers throughout the neighborhood, enticing readers with discounts on the latest releases and upcoming author signings.

Collocations with flier:
Some most commonly used collocations include:
1. Discount flier: a flier advertising sales, discounts, or special offers.
I always check the mailbox for discount fliers from local stores before going shopping.
2. Business flier: a flier used for promoting a business or its services.
The startup created a business flier to introduce their services to potential clients.
3. Recruitment flier: a flier designed to attract individuals to join a group, organization, or cause.
The university posted recruitment fliers around campus to encourage students to join the new club.
4. Safety flier: a document providing information and tips on safety measures.
The workplace distributed safety fliers to employees, emphasizing the importance of following guidelines.

Correct spelling, explanation: the difference between flyer and flier primarily lies in regional preferences and context, but it’s essential to note that both terms are considered correct. Flier is the more common spelling in American English, and it is typically used for both a person or thing that flies and a handbill or promotional piece of paper. In British English, flyer is very commonly used, though flier is gaining acceptance. It can be used similarly to both meanings mentioned above.