Semifinal vs. meia-final
Both semifinal and meia-final refer to the penultimate round of a competition or tournament. The primary difference is regional: semifinal is the standard term in Brazilian Portuguese, while meia-final is the predominant term in European Portuguese.
Semifinal
B1This word describes the round just before the final. It is the exclusive term used in Brazil for all contexts, from sports to talent shows. While it exists in European Portuguese dictionaries, it is less common than meia-final in daily speech there.
O Brasil venceu a semifinal e agora vai disputar o ouro.
(Brazil won the semifinal and will now compete for gold.)
Ninguém esperava que eles perdessem na semifinal do campeonato.
(No one expected them to lose in the championship semifinal.)
Os ingressos para a semifinal já estão esgotados.
(Tickets for the semifinal are already sold out.)
Ela foi eliminada na semifinal do programa de culinária.
(She was eliminated in the cooking show's semifinal.)
Meia-final
B1This term also refers to the round preceding the final match. It is the standard and most frequently used term in Portugal and Portuguese-speaking African countries. Note that the plural form is usually written as meias-finais.
A equipe de Lisboa chegou à meia-final da taça.
(The Lisbon team reached the cup semifinal.)
Foi uma meia-final muito emocionante para os adeptos.
(It was a very exciting semifinal for the fans.)
As duas meias-finais serão jogadas no mesmo estádio.
(The two semifinals will be played in the same stadium.)
O tenista espanhol garantiu o seu lugar na meia-final.
(The Spanish tennis player secured his place in the semifinal.)
Summary
Use semifinal if you are speaking or writing in Brazilian Portuguese. Use meia-final if you are communicating in European Portuguese. While both are intelligible across regions, adhering to these preferences ensures you sound naturally local.