Noun
(business) A company operating in only one industry or line of business; often specifically a bank specializing in credit card issuance.
(finance) An insurer specialized in insuring investment-grade securities against loss.
(calligraphy) A font line of consistent width, as occurs when imitating pencil script.
(aquaculture) A length of monofilament line, used for culturing forms of seaweed.
(printing, dated) A type of composing machine in which each line of type is cast as a single slug.
(spectroscopy) A single spectrum line.
Source: en.wiktionary.org