1. to choose or pick something unintentionally, without meaning to do so
I accidentally selected the wrong file when trying to open the document.
Eu selecionei acidentalmente o arquivo errado ao tentar abrir o documento.
2. to highlight or mark something by mistake in a digital interface
She accidentally selected all the text when she meant to click elsewhere.
Ela selecionou acidentalmente todo o texto quando pretendia clicar em outro lugar.