If you are a millennial or even a Gen Z, you probably grew up hearing the word "Belgium" when people were referring to second-hand goods.
Due to cheap production costs, Belgium produced the majority of Europe's products in the 1970s and 1980s.
Additionally, one of the major European exporters of secondhand clothes and other commodities to Nigeria and other African nations was Belgium.
Eventually, "Belgium" evolved to mean all used goods, regardless of where they came from.
When compared to goods from other countries, used goods from Belgium were frequently thought to be of better quality, with sellers boasting that their wares are ‘Direct Belgium.’
This impression strengthened the connection between used goods and "Belgium." Nigerians originally imported things from Europe before turning to other countries.
Therefore, "Made in Belgium" was written on most of the imported goods just as we see a lot of “Made in China”. Nigerians also refer to secondhand items these days as "UK-used," even though they do not come from the UK.
These goods are actually from the United Kingdom, Europe, the United States of America, and Asia.
Also, if there’s one thing Nigerians love, it’s a catchy phrase.
Once a phrase becomes popular, it is ingrained in Nigerian slang and lingua.
It is because of these historical and cultural reasons that used clothing in Nigeria is referred to as "Belgium" informally.
These days thrifted clothes are also referred to as Okrika or bend-down-select, and other second-hand goods like cars and household appliances are called Tokunbo.