Origin: Latin suffix -al
Formal has 11 different meanings across 2 categories:
a gown for evening wear
"She decided to rent a floor-length formal for her upcoming gala."
An evening gown.
"The biology teacher asked students to wear gloves before handling the formalin preserved in the jars."
Formalin.
In plain English: A formal is an official written document used to present evidence or arguments in a court of law.
"The formal at the wedding was very stiff and uncomfortable."
Usage: As a noun, formal refers specifically to formaldehyde dissolved in water, commonly known as formalin. It is used primarily as a disinfectant or preservative for biological specimens and should not be confused with the adjective describing official events or attire.
being in accord with established forms and conventions and requirements (as e.g. of formal dress)
"pay one's formal respects"
"formal dress"
"a formal ball"
"the requirement was only formal and often ignored"
"a formal education"
(of spoken and written language) adhering to traditional standards of correctness and without casual, contracted, and colloquial forms
"the paper was written in formal English"
represented in simplified or symbolic form
"The architect chose to represent the complex structural load-bearing system in a formal diagram before presenting it to the client."
Being in accord with established forms.
"The ceremony followed every formal tradition, from the precise bow to the reading of the ancestral names."
In plain English: Formal means following official rules and behaving very politely instead of being casual or relaxed.
"The meeting was very formal because everyone wore suits and shook hands upon arrival."
Usage: Use formal to describe situations, events, or language that follow strict rules and conventions, such as black-tie galas or official ceremonies. Avoid using it for casual gatherings unless you are specifically highlighting the contrast with informal settings.
The word formal comes from the Latin fōrmālis, which is derived from fōrma meaning "shape" or "model." It entered English through Middle French and originally described something that had a definite shape, eventually taking on its current sense of being official or conventional.