Thickness of an object — the measurement of how thick something is (e.g., a board or book).
この板の厚みは20ミリです。
This board is 20 millimeters thick.
本棚に並べる前に、本の厚みを測った。
Before putting them on the shelf, I measured the thickness of the books.
生地の厚みが違うと、服の暖かさも変わる。
If the fabric's thickness differs, the warmth of the clothing also changes.
Profundity or depth — figuratively refers to richness or weight in content or expression.
彼の小説には人生経験に裏打ちされた厚みがある。
His novel has a depth backed by life experience.
議論にもう少し厚みが欲しいなら、具体例を増やすといい。
If you want more depth in the discussion, add more concrete examples.
In the game of Go, 'thickness' refers to a strong, solid formation of stones that provides influence and stability.
その布石は相手にプレッシャーを与える厚みを作っている。
That opening strategy creates a thickness that puts pressure on the opponent.