fog up
US /fɑːɡ ʌp/
UK /fɑːɡ ʌp/

1.
embaçar, cobrir-se de vapor
to cover with a film of condensed water vapor, as from breath or steam, making it difficult to see through
:
•
The bathroom mirror always fogs up after a hot shower.
O espelho do banheiro sempre embaça depois de um banho quente.
•
My glasses fogged up when I came inside from the cold.
Meus óculos embaçaram quando entrei do frio.
2.
embaçar, ficar confuso
to become confused or unclear in thought or understanding
:
•
My mind tends to fog up when I'm tired.
Minha mente tende a embaçar quando estou cansado.
•
The complex instructions made my brain fog up.
As instruções complexas fizeram meu cérebro embaçar.