Word: tidemark
Part of speech: Noun
Syllables: tide
mark
Definition: a line (of seaweed or differently coloured sand etc) on the shore showing the level of high or low tide
Morphemes:
Affix: tide
Language: en
PoS: Noun
Meaning: Something which changes like the tides of the sea.
Affix: mark
Language: en
PoS: Noun
Meaning: A boundary; a border or frontier.