куда́
adverb
which way; whither poetic
(to) where?
Куда́ идёшь?
Where are you going?
conversational
in a comparison
much (more), a lot (more)
Настоя́щая причи́на звуча́ла куда́ прозаи́чнее.
The real reason was far more prosaic.
used in the following idiomatic expressions