With the stroke of a sharpie last week, President Trump moved to re-designate Lake Ontario, the long-established name for the freshwater lake that lies between New York State and the Canadian province of Ontario, to “Lake America.”

The executive order came amid an escalating trade war with Canada after negotiations over tariffs fell apart, followed by new tariffs and tough talk between Washington and Ottawa.

Like Mr. Trump’s order to rename the Gulf of Mexico to the Gulf of America, last week’s order required only federal entities to recognize the change, but was not binding on other countries.

Lake Ontario thus joined an extensive group of bodies of water with disputed names. Though for some there is no dispute. Prime Minister Mark Carney of Canada spiked searches for the word “hydronym,” which means a body of water’s proper name, by more than 5,000 percent in a statement lamenting a changing America.

The United States’ latest rechristening is mostly about “rage-bating and trolling Canadians,” said Reuben Rose-Redwood, a professor of geography at the University of Victoria in Canada.

He said the tiff surrounding Lake Ontario lacks the deep symbolism and geopolitical stakes of some more longstanding naming disputes.

But “that doesn’t mean it doesn’t have serious consequences,” Mr. Reuben Rose-Redwood added. He said maps have long been used to project power and influence.

“If we look back in history, you have colonizing powers using place names to assert their control over different areas,” he said.

Mark Iliffe, a geographer with the group, said names matter because they are imbued with a sense of identity and place.

“We care because it’s about who we are,” he said.

But the issue is not merely abstract, he said. While it’s common for the name of a town, river or nation to differ based on language or historical perspective, naming disputes can persist because they are tied to competing claims over territory or historical narratives. Additionally, Mr. Iliffe said, standardization makes it easier to draft international legal documents and respond quickly to distress calls in emergency situations.

Here are some other bodies of water around the world caught up in naming controversies.

Sea of Japan or the East Sea?

The waters that lie between the Korean Peninsula and Russia to the north, and Japan to the east, have three different names depending on whom one asks.

While Japan identifies the area after its own name, South Korea has long maintained that it should be called the East Sea. North Korea, for its part, officially prefers “Korean East Sea” or “East Sea of Korea.”

On official sites, the government of Japan says its preferred name has been used with “overwhelming frequency” since the early 19th century, and chides “unfounded arguments” for any other moniker. South Korea’s foreign ministry asserts that the name “East Sea” has been used in Korea for more than 2,000 years.

The dispute has long been a headache for the International Hydrographic Organization, which promotes standardization and data collection on the world’s marine environment. The group published its first global maps which listed the “Sea of Japan” in the late 1920s, at a time when the Empire of Japan ruled Korea as a colony.

The organization has since sidestepped the controversy, along with others mentioned below, by using numerical identifiers for bodies of water, instead of names.

Persian Gulf or Arabian Gulf?

The body of water that is surrounded by Iran and several Arab nations is also subject to decades of wrangling over what it should be called.

It has been called the Persian Gulf throughout history, on maps, in documents and in diplomacy, from the ancient Persians, whose empire dominated the region, to the Greeks and the British.

But a push to call it the Arabian Gulf gathered steam during the Pan-Arab nationalist movement, which began in the 1950s. By the 1960s, Arab countries made “Arabian Gulf” compulsory, and it is the preferred term of the Gulf Cooperation Council.

Mr. Trump suggested the name should be changed to the “Arabian Gulf” last year, drawing Iran’s ire.

South China Sea or West Philippine Sea?

Several countries claim and have names for the waters south of China, which the Chinese and much of the international community call the South China Sea. As one example, the Philippines calls the waters to its west, “the West Philippine Sea.” (In the Chinese language, it is referred to simply as Nanhai, or “South Sea.”)

The naming conflict flows from a protracted and complex set of territorial disputes over sovereignty and resources in the South China Sea. Portions of the waters — and the important minerals and islands within them — are claimed by Taiwan, China, Vietnam, Malaysia, Brunei, Indonesia and the Philippines.

In recent years, China’s coast guard ships have swarmed and collided with Philippine boats. They have doused Philippine vessels with powerful water cannons. Chinese crew members have slashed inflatable crafts, blared sirens and flashed high-powered lasers at Filipino troops.