Englishfor English speakers
Co
—
noun
(= cobalt)
a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
CO
—
noun
(= conscientious objector)
one who refuses to serve in the armed forces on grounds of conscience
—
noun
(= Colorado)
a state in west central United States in the Rocky Mountains
—
noun
(= carbon monoxide)
an odorless very poisonous gas that is a product of incomplete combustion of carbon
proto
—
adjective
indicating the first or earliest or original
'proto' is a combining form in a word like 'protolanguage' that refers to the hypothetical ancestor of another language or group of languages