How to Say "flap" in Spanish
The Spanish word for “flap” is “pestaña” — A2 level. This is a very common word in everyday Spanish.
English → SpanishA2
nounA2
a small piece of material on a box or envelope

Examples
Tengo demasiadas pestañas abiertas en mi navegador.
I have too many tabs open in my browser.
Haz clic en la pestaña de 'Archivos' para ver los documentos.
Click on the 'Files' tab to see the documents.
Dobla la pestaña de la caja hacia adentro.
Fold the flap of the box inward.
Computer Language
Just like in English where a 'tab' can be on a folder or a browser, 'pestaña' works for both physical file folders and digital windows.
Tab Key vs. Browser Tab
Mistake: “Pressing the 'pestaña' key on the keyboard.”
Correction: The key on your keyboard is called 'tabulador' or 'tecla Tab,' not 'pestaña.'
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