This is the 551st most frequent Danish word.
vidste
"Vidste" means "knew" in English.
In this sentence, 'vidste' is used to express a question regarding a past state of knowing or being informed.
Vidste du, at det skulle regne i dag?
Did you know that it would rain today?
'Vidste' is employed here to depict a past state of knowledge about an event that occurred in the past.
Han vidste, hvad der var sket i går.
He knew what had happened yesterday.
Here 'vidste' is the past tense of the verb 'vide', conveying a past realized state of not knowing.