For seasoned equity, having gained a reputation for quality with the investing public and enjoying liquidity in the secondary market ; when applied to convertibles, having traded for at least 90 days after issued in Europe, and is thus available for sale legally to U.S. investors.
SEASONED
Meaning of SEASONED in English
Campbell R. Harvey. Hypertextual finance English glossary. Английский словарь гипертекстовых финансов. 2012