marl 
(märl)
(märl)n.
A crumbly mixture of clays, calcium and magnesium carbonates, and remnants of shells that is sometimes found under desert sands and used as fertilizer for lime-deficient soils.
tr.v. marled, marl·ing, marls
To fertilize with such a mixture.
[Middle English marle, from Old French, from Medieval Latin margila, marla, diminutive of Latin marga, marl, of Celtic origin.]
marly adj.
- unicellularity
- Unicode
- unicolor
- unicorn
- unicorn plant
- unicostate
- unicuspid
- unicycle
- unicyclist
- unidentified flying object
- unidimensional
- unidirectional
- unidirectionality
- unidirectionally
- uniface
- unifacial
- unifacially
- unifactorial
- unifiable
- unification
- Unification Church
- unified field theory
- unifier
- unifilar
- unifloral