1. trifold - Noun
2. trifold - Adjective
threefold
Of a mirror: having three reflective surfaces hinged together.
Any sheet of paper or cardboard, folded into three sections along two parallel creases and used to present information, typically as a brochure or display board.
A wallet with three equal-sized sections that fold together.
Anything folded into thirds to resemble a trifold.
Source: en.wiktionary.org