A relatively narrow tubular passage or channel.
Acronyms for organizations that administer or develop national and international standards. ANSI (American National Standards Institute) is the national organization established for the purpose of accrediting and coordinating product standards development activities in the United States. It is not a US government agency. The ADA (American Dental Association) is a national standards development organization accredited by ANSI. ISO (International Organization for Standardization) is a worldwide federation of national standards bodies. The results of ISO technical work are published as International Standards. Efforts in the United States directed toward the development of ISO standards are channeled through ANSI.