thick, heavy, rich, kind, cordial, brazen, shameless
厚 centers on physical or figurative depth and abundance: something thick, heavy, or rich. Its interpersonal meanings (kind, cordial) extend the idea of generous depth, while brazen or shameless behavior can be seen as a thick-skinned lack of restraint.
厚 combines 厂 (cliff) with an inner component historically associated with thickness or depth. The exact origin of the inner part is uncertain, but the character has long expressed the idea of thick or generous.
Under a cliff (厂), a child (子) basks in the sun (日). The cliff provides a thick, heavy shelter, and the scene feels rich and kind—like a generous, cordial embrace. But if the child gets too bold, they might act brazen or shameless under that thick protection.
For コウ, imagine a thick, heavy coat (コート) hanging under the cliff: coat -> コウ, and its thickness matches the kanji's core meaning.
thickness
welfare; public welfare; social welfare
rich (flavor, color, etc.); strong (e.g. odor); heavy; thick (soup, makeup, etc.); dense
thick; deep; heavy
thick; bulky; massive; heavy
thickness
warm (treatment, reception, etc.); kind; cordial; hospitable; courteous; respectful
profound; deep; grave; solid; dignified; stately; solemn; composed; substantial; massive
gentle; mild-mannered
elm bark clothes traditionally worn by the Ainu; elm bark textile
kindness (shown by others); courtesy; favor; favour; good offices
(former) Ministry of Health and Welfare
impudent; shameless; brazen; cheeky; presumptuous
thick soles; thick-soled footwear
thick (paper, cloth, etc.); heavy
cardboard; thick paper
wearing thick clothes; dressing warmly
somewhat thick; relatively thick; thickish; on the thick side
cordial welcome; hearty welcome; kind treatment; hospitality
thick makeup; heavy makeup