Marl \Marl\, v. t. [See Marline.]

(Naut.) To cover, as part of a rope, with marline, marking a pecular hitch at each turn to prevent unwinding.

Marling spike. (Naut.) See under Marline.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Marl \Marl\, n. [OF. marle, F. marne, LL. margila, dim. of L. marga marl. Originally a Celtic word, according to Pliny, xvii. 7: ``Quod genus terr[ae] Galli et Britanni margam vocant.'' [root]274.]

A mixed earthy substance, consisting of carbonate of lime, clay, and sand, in very varivble proportions, and accordingly designated as calcareous, clayey, or sandy. See Greensand.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Marl \Marl\, v. t. [imp. & p. p. Marled; p. pr. & vb. n. Marling.]

[Cf. F. marner. See Marl, n.]

To overspread or manure with marl; as, to marl a field.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Greensand \Green"sand`\ (-s?nd`), n. (Geol.) A variety of sandstone, usually imperfectly consolidated, consisting largely of glauconite, a silicate of iron and potash of a green color, mixed with sand and a trace of phosphate of lime.

Note: [hand]Greensand is often called marl, because it is a useful fertilizer. The greensand beds of the American Cretaceous belong mostly to the Upper Cretaceous.

Source: Webster's Revised Unabridged Dictionary (1913)