Definition of tidemark in US English:

tidemark

noun

  • A mark left or reached by the sea on a shore at the highest or lowest point of a tide.

    • ‘In a review article, he concluded that physical factors were most important to determine the upper and lower limits of intertidal communities, but biological factors predominated in life between the tidemarks.’
    • ‘I have seen them feeding at the tidemark with snow buntings and pipits and they also find seeds in the marram hills.’
    • ‘It was, I felt, scenically enhanced by its proximity to the Dodder River, even though it was the cause of the water tidemarks on the internal walls, the area having flooded a few years back.’
    • ‘When a high tide occurs and the tidemark reaches beyond the normal beach line, this tends to create certain element of fear in the people.’

Pronunciation

tidemark

/ˈtīdˌmärk//ˈtaɪdˌmɑrk/