It's pretty obvious what we mean by South America, Argentina, the Southern Hemisphere, and the world outside Asia. But what is the Western Hemisphere?
According to Britannica, it's the "part of Earth comprising North and South America and the surrounding waters. Longitudes 20° W and 160° E are often considered its boundaries. Some geographers, however, define the Western Hemisphere as being the half of Earth that lies west of the Greenwich meridian (prime meridian, 0° longitude) continuing to the 180th meridian. According to this scheme, the Western Hemisphere includes not only North and South America but also portions of Africa, Europe, Antarctica, and Asia."
I personally would have gone for the latter definition: everything that's west of the Greenwich meridian and east of the 180th meridian (or the International Date Line). The US State Department has a graphic which shows pretty much this part of the globe, but as "Countries Comprising the Western Hemisphere Region" it only lists those in the Americas and the Caribbean – even though the graphic shows parts of West Africa and Western Europe (including the British Isles).
(Presumably because it's something to do with the USAID Strategic Plan, it also doesn't list the United States!)
© Haydn Thompson 2022