1) I heard someone said "Погади" to her little kid. I figured it means "wait" but I never heard this word before. This word did not appear in my dictionary. I only found the translation via a wiki article that has an animated soviet film called "Ну погади" (Just you wait).

Is there a difference between погади and подажди?



2)
хитрость (trick) is female according to the dictionary, but it doesn't end with "a"!

So, my question is, when using adjectives to describe this noun, do I use them in female form?

i.e.

Old trick - старая хитрость