The American Heritage® Dictionary of the English Language, 4th Edition
adj. Of, relating to, or constituting an organic compound containing a metal, especially a compound in which a metal atom is bonded directly to a carbon atom.
adj. of, or relating to organic compounds having a metal atom directly bonded to a carbon atom
n. Any organometallic compound.
the GNU version of the Collaborative International Dictionary of English
adj. Pertaining to, or denoting, any one of a series of compounds of certain metallic elements bound to organic radicals; such as, methylmercury, zinc methyl, sodium ethyl, etc.; formerly refered to as metalorganic.
The Century Dictionary and Cyclopedia
In chem., an epithet applied to compounds in which an organic radical, as ethyl, is directly combined with a metal, to distinguish them from other organic compounds containing metals, in which the metal is indirectly united to the radical by the intervention of oxygen.
Word Usage
"Instead of using metals to propel a chemical reaction (a standard method called organometallic catalysis widely used in the creation of pharmaceuticals), the team developed a way to use organic chemicals such as carbon in the reaction, an environmentally safer, easier and cheaper way to produce drugs."