Definition of "tertiary" []

• Third in place, order, degree, or rank. (adjective)
• Of, relating to, or designating the short flight feathers nearest the body on the rear edge of a bird's wing. (adjective)
• Chemistry Of or relating to salts of acids containing three replaceable hydrogen atoms. (adjective)
• Chemistry Of or relating to organic compounds in which a group, such as an alcohol or amine, is bound to three nonelementary radicals. (adjective)
• Of or belonging to the geologic time, system of rocks, or sedimentary deposits of the first period of the Cenozoic Era, characterized by the appearance of modern flora and of apes and other large mammals. See Table at geologic time. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It would be better for government to focus on its core competency (safety regulation) and let the other fall by the wayside, but at least separating the primary from the tertiary is a good first step."
• ""That's what they call tertiary recovery," Clark said."
• ""The lower tertiary is recognized as a huge resource with the potential for long life projects of up to 30 to 40 years," said Chevron Vice Chairman George Kirkland in prepared remarks."