Meaning of gelten

Was bedeutued ‘gelten’. Es scheint ganz verwirrend, wann man Wörterbuch an sieht.
What is the meaning of “gelten”. It seems confusing when you look it up in a dictionary.

(originally asked by Conanon, thank you)

What does scharf mean?

In English ‘sharp’ is used fairly regularly to mean ‘clever,’ at least in the positive sense (quick-witted, keen, intelligent, etc.). Is it not the same with the German ‘scharf’?

(originally asked by Trevor, thanks a lot)