tidemark
Stain showing flood's peak
A tidemark is a line or mark showing the highest or lowest point reached by a tide or other body of water.
The term extends to any visible boundary left by liquid—the grimy ring around a bathtub, or the line on a glass showing where a drink once stood.
In British usage, it can describe a visible dirt line on skin, particularly on a child who hasn't washed thoroughly: He had tidemarks on his neck.
Land-water boundary
- seashoreOcean's edge
- beachSandy waterside margin
- foreshoreIntertidal coastal zone
- littoralRelating to seashores
high-water · strand · flotsam · jetsam · driftwood · seaweed · kelp · barnacles
Translucent authentication mark
- ringClosed curve shape
- residueMatter left behind
- discolorationAltered surface pigmentation
- streakUnbroken series
line · deposit · calcium · limescale · scum · sediment · crust · film
Single unit of information
- benchmarkStandard for comparison
- baselineStandard for comparison
- gaugeStandard of measurement
- measureUnit of quantity
boundary · demarcation · limit · extent · reach · peak · maximum · record
shoreline
Land-water boundary
littoral · high-water · strand · flotsam · jetsam · driftwood · seaweed · kelp · barnacles · mussels
watermark
Translucent authentication mark
- ringClosed curve shape
- residueMatter left behind
- discolorationAltered surface pigmentation
streak · line · deposit · calcium · limescale · scum · sediment · crust · film · scale
datum
Single unit of information
measure · boundary · demarcation · limit · extent · reach · peak · maximum · record · historical
benchmark
Standard for comparison
pinnacle · peak · zenith · nadir · standard · measure · yardstick · reference · achievement · record
berm
Raised strip alongside roads
spit · tombolo · foreshore · backshore · dune · cusps · shingle · pebbles · sand · silt
- tidesebb, slack water, ebb and flow, flow, Bay of Fundy
- beachcombingseashell, shells, driftwood, sea glass, sand dollar