ground-line
[Cf. Du. grondlijn, G. and Sw. grundlinie (in senses 2 and 3).]
1. A line used for bottom-fishing. ? Obs.
| a 1450 Fysshynge w. angle (1883) 22 Ye may angle to hym at all tymys with a grownde lyne. 1704 Dict. Rust. s.v. Ground-angling, The Morning and Evening are the chiefest seasons for the ground Line for Trout. |
2. Geom. † a. The base upon which a diagram is constructed (obs.). b. (See quot. 1857).
| 1551 Recorde Pathw. Knowl. i. Defin., When one line lyeth flatte (whiche is named the ground line) and an other commeth downe on it, and is called a perpendiculer. 1571 Digges Pantom. i. iii. C j, Measure out the like length in the perpendiculare..beginning from the ground line. 1659 Willsford Scales Comm. 118 Let fall a Perpendicular..upon the Basis or ground-line. 1857 W. Binns Treat. Orthogr. Project. i. (1862) 2 The vertical and horizontal planes are generally divided by a line called the ground line, or intersecting line of the two planes of projection. |
3. pl. Outlines (lit. and fig.).
| 1624 Wotton Archit. i. 65 Let no man..setle his Fancie vpon a draught of the Worke in paper..much less vpon a bare Plant thereof, as they call the Schiographia or Ground lines. 1858 J. Martineau Stud. Chr. 150 We owe to the deeper Evangelical spirit..the ground-lines of an Ethical philosophy. |
______________________________
Add: 4. Show-jumping. The line along the base of a fence formed where the obstacle meets the ground, and used in judging the point of take-off; hence, any marker placed to assist the horse and rider in this way.
| 1951 M. P. Ansell Show Jumping i. 14 A fence, such as a wall, which rests on the ground, has a distinct ground line: a single rail has no ground line, making this obstacle difficult. 1986 Riding May 30/2 For this we have a placing pole,..then a distance of 10 to 10½ yds to the second fence, which is a parallel with a bold groundline. |