dag

Dag is a masculine given name in Sweden and Norway, and also occurs as a surname. It originates from the Old Norse dagr, meaning “day.” The name has been used since medieval times and remains common in Scandinavian countries. Notable people with the name include Dag Hammarskjöld (1905–1961), Swedish economist and diplomat who served as United Nations Secretary-General, and Dag Wirén (1916–1986), Swedish composer of the neoclassical era.

In Dutch and Afrikaans, dag means “day” and is also used as a casual greeting, Dag, similar to “hello” in English contexts.

In computing, DAG stands for Directed Acyclic Graph, a data structure in which edges have a direction and there are no cycles. DAGs are used to model task schedules, data processing pipelines (for example, Apache Airflow and other workflow engines), and certain distributed ledgers. Some blockchain and distributed ledger projects use DAG-based approaches, such as IOTA’s Tangle.

In biochemistry, DAG is the acronym for diacylglycerol, a glyceride molecule that acts as an intracellular second messenger in signaling pathways.