厚 (hòu) as an adjective has two main uses: describing the physical thickness of flat objects, and describing a person's generous, kind character. For physical thickness, it's the basic word; 浓厚 (nóng hòu) and 浓重 (nóng zhòng) are used for dense fog, strong flavors, or rich colors, not for flat objects. For character, 厚 is a general term; 厚道 (hòu dao) specifically means kind and honest, while 宽厚 (kuān hòu) emphasizes tolerance.