What is the meaning of the word "crisp"?

Definitions:

a thin crisp slice of potato fried in deep fat noun
- I had a bag of crisps for lunch.
brief and to the point adjective
- I wasted no time and sent a crisp email.
in small tight curls, of hair adjective
- The baby had beautiful crisp blond hair.
of something seen or heard clearly defined adjective
- The new radio produced a crisp tone.
pleasantly cold and invigorating adjective
- Crisp clear nights are my favourite.
pleasingly firm and fresh adjective
- My salad was full of crisp lettuce.
tender and brittle adjective
- The crisp leaves crackled underfoot.
to make brown and crisp by heating verb
- I crisped the kale in the oven.