[{"Bold_text": "noun", "List Items": ["the fourth letter of the Greek alphabet (?, ?).", "the consonant sound represented by this letter.", "the fourth in a series of items.", "anything triangular, like the Greek capital delta (?).", "Mathematics.an incremental change in a variable, as ? or ?.", "a nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular:the Nile delta.", "Also Delta.a word used in communications to represent the letter D.", "Delta,Astronomy.a star that is usually the fourth brightest of a constellation:The fourth brightest star in the Southern Cross is Delta Crucis."]}, {"Bold_text": "noun", "List Items": ["the NATO name for a class of nuclear-powered submarines armed with multiple-warhead ballistic missiles, including those designed to strike military and industrial installations: first produced for the Soviet Navy in the 1970s; in service with the Russian Navy since 1992."]}]