
Sweatshirt
It is fairly certain that people were wearing sweatshirts (“a loose collarless pullover or jacket usually of heavy cotton jersey”) well before 1925, but we just hadn’t yet gotten around to calling them by this name. This is not unusual with words for articles of clothing: there are a number of other items that appear to have been named in the 1920s, such as underpants and sweatpants, that had been invented well before then.
Most of the fellows were wearing sweat-shirts. You know what they are. They are those jerseys that athletes wear.
— The Spokane Press, 9 Nov. 1925

Surrealism
It can be difficult to pinpoint exactly when surrealism (“the principles, ideals, or practice of producing fantastic or incongruous imagery or effects in art, literature, film, or theater by means of unnatural or irrational juxtapositions and combinations”) began; the word itself was used in French by Guillaume Apollinaire in 1917, and again in 1924 by André Breton in his Manifeste du Surréalisme. In English use our earliest record comes in 1925. The word surreal, now far more common than surrealism, did not enter the language until the 1930s.
Some of the erstwhile titans have become successful writers in Hungary. They went home imbued with the sacred teachings of surrealism.
— The New York Times, 23 Aug. 1925

Omphaloskepsis
Our earliest record of omphaloskepsis, meaning “useless or excessive self-contemplation,” is in a 1925 Aldous Huxley novel, Those Barren Leaves. The word comes from the Greek omphalós (“navel”) and sképsis (“examination”). Omphaloskepsis may additionally mean “contemplation of one's navel as an aid to meditation.”
Three love affairs proceed simultaneously. The novelist and the guardsman have theirs, which provides the woman with personal experience, of which she makes constant mental notes, to be used in future writing. To the man it gives the final impetus towards retirement into solitude and what is, in the Huxleyan manner, described as omphaloskepsis.
— Town and Country, 1 Apr. 1925

Jive
Jive hit the English language a century ago, and has had a very successful career. The word’s earliest meaning was “glib, deceptive, or foolish talk,” but it soon after took on additional meanings, including “a special jargon of difficult or slang terms,” “swing music or the dancing performed to it,” and “to talk in a foolish, deceptive, or unserious way.”

Motel
The growing automobile industry of the 1920s helped create a number of new terms; among the best known of these is motel. The word (which we define as “an establishment which provides lodging and parking and in which the rooms are usually accessible from an outdoor parking area”) is a blend of motor and hotel.
Hostelry Chain for Motorists - "Motels" is Name for New Caravansary System - Every Convenience Planned for Tired Tourist - Company to Build One for Each Day's Journey
— (headline) Los Angeles Times, 18 Jan. 1925
Other automobile-related words that came into use in 1925 include gas station, bumper to bumper, and speedtrap.

Recycle
In modern use, recycle is most often used in the sense “to process materials or substances (such as liquid body waste, glass, or cans) in order to regain material for human use.” When the word first came into use it was in a patent awarded at the end of 1925, with the spicy title of Recovery of phenols from ammoniacal liquor.
With such cyclic operation, it is readily possible to recycle sufficient ammonia to insure that substantially all of the phenolic compounds will be driven off so that they may be recovered, and so that the waste liquor from the still will be freed from objectionable phenolic constituents.
— U.S. Patent 1,566,796

Group Therapy
Therapy, with the meaning of “medical treatment of impairment, injury, disease, or disorder,” has been a part of the English language since the first half of the 19th century, but we did not begin engaging in this in groups until 1925 (at least that’s when we first began referring to multiple people engaging in this as group therapy).
In the second place, his system of ‘group-therapy’ was attacked on the grounds that it took no account of the individual as a separate case and did not indeed trouble to make a preliminary examination of him.
— Karl Abraham, The International Journal of Psycho-Analysis, 1 Jan. 1926