What is "carbamic acid"

Carbamic \Car*bam"ic\ (k[aum]r*b[a^]m"[i^]k), a. [Carbon + amido.] (Chem.) Pertaining to an acid so called.

Carbamic acid (Chem.), an amido acid, H2N.CO2.H, not existing in the free state, but occurring as a salt of ammonium in commercial ammonium carbonate; -- called also amido formic acid.

n. (context organic compound English) amino-formic acid, NH₂COOH; it is too unstable to have been isolated, but its esters and salts are known.

n. an acid that is known only by virtue of its salts (as ammonium carbamate) or its esters (as urethane)

Carbamic acid is the compound with the formula NHCOOH. The attachment of the acid group to a nitrogen or amine (instead of carbon) distinguishes it from carboxylic acid and an amide. Many derivatives and analogues of carbamic acid are known. They are generally unstable, reverting to the parent amine and carbon dioxide. The deprotonated anion (or conjugate base) of this functional group is a carbamate. Carbamic acid is a planar molecule.