groundline

About 0.01 uses per million words.

Meaning

1. noun A line drawn to signify the surface of the ground, especially in architectural blueprints and in drawings by children which lack dimension.
2. noun In equestrian show jumping, a marker such as a row of flowers which signifies the point from which a horse should begin a jump over an obstacle.
3. noun A weighted fishing line that lies along the floor of the body of water in which the user is fishing.

Similar words

outline gridline baseline neatline groundplan plumb line occult line skyline level strandline

Often followed by

and of diameter is to with