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1. A line or mark on a shore indicating the highest or lowest level reached by the tide.
2. A trace or indication of past activity: "Just along the highway into town is the last tidemark of the Nazi advance, a brutal tangle of brown sculpture" (Regina Nadelson).
1. (Physical Geography) a mark left by the highest or lowest point of a tide
2. (Physical Geography) a marker indicating the highest or lowest point reached by a tide
3. chiefly Brit a mark showing a level reached by a liquid: a tidemark on the bath.
4. informal chiefly Brit a dirty mark on the skin, indicating the extent to which someone has washed
1. the point reached or risen above: the tidemark of our prosperity.
2. a mark left by the highest or lowest point of a tide.
3. a mark indicating such a point.