Buckle up and buck up are two idioms that appear to be similar, but have very different meanings. An idiom is a word, group of words or phrase that has a figurative meaning that is not easily deduced from its literal definition. We will examine the definitions of buckle up and buck up, where they came from and some examples of their use in sentences.
The expression buckle up is used in a literal sense to admonish someone to fasten his seat belt. Buckle up is also used in a figurative sense to warn someone that something exciting, frightening or otherwise intense is about to happen. One might warn a friend to buckle up before relating a hair-raising story. Buckle up has been used for a long time in advertising campaigns encouraging drivers to fasten their seat belts. The use of buckle up as an idiom appeared at about the same time that seat belts were installed in passenger cars in the United States, in the 1960s. However, the sentiment was expressed earlier in the 1950 movie All About Eve by the character Margo Channing: “Fasten your seat belts, it’s going to be a bumpy night.”
Buck up is an admonition to toughen up or to cheer up. Buck up may be used to demand that someone quit acting in a cowardly or weak fashion, or to encourage someone to look on the bright side of life and not dwell on negative things. Buck up was first used in the 1800s, though at that time it meant to dress in a smart manner.
Examples
“As law enforcement, we have a special role in helping protect the safety of our citizens; we want to make sure that motorists ‘buckle up’ to keep themselves and their families safe” said Greg Rittger, the motor unit’s master deputy. (The Orlando Sentinel)
“Buckle up, it’s going to be a bumpy ride for the pound this week.” (Reuters)
“I talked to my sprint coach, John Mays, and he said, ‘At this point, he’s going to have to buck up, because there’s nothing we can do with that,'” Benson coach Leon McKenzie said. (The Portland Tribune)
If one was stressed, the response was often, “buck up” or “get over it.” (The Deseret News)