Clarity
Clarity adds contrast in the midtones, mostly around edges and textures. It makes your photo crisper and gives depth without hardening the whole image. In Lightroom and Camera Raw you'll find the slider in the basic panel.
Push clarity up a little for more punch in landscapes, architecture or gritty portraits. Be careful with faces: too much clarity emphasizes pores and blemishes, so dial it back for soft portraits. If you want structure without the hard edge clarity gives, try texture. Negative clarity creates a dreamy, soft glow that works beautifully on wedding photos.
Read also the in-depth explanation: Clarity explained.
Related terms
Prefer a look in one click?
The presets on this site set these adjustments up for you as a starting point, which you then fine-tune to taste.