Airports and the businesses around them do not always use the same words for the same thing. A duty manager says congestion. A cafe manager says a queue that will not clear. A developer reading a payload sees a field name and a level. All three are describing the same afternoon.
This glossary exists so that everyone on your side of the counter reads a DwellTime signal the same way. These are not general aviation definitions. They are the definitions the product works to, and they are used consistently in three places: the language on this website, the labels in the dashboard, and the field names in the API.
That consistency matters more than it sounds. Dwell time and dwell-time pressure are not the same thing, and mixing them up changes what you would do about a signal. One describes time spent in a terminal. The other is a risk score about time that has not happened yet. A term used anywhere on this site means exactly what its glossary entry says, no more and no less.
Every entry follows the same shape. A plain definition first, written so it can stand on its own. Then why the term matters to a business operating near a terminal, tied to a decision someone actually makes: a shift, a stock order, a driver, a room. Then how the term appears inside the product, including the field name where one exists. Then links to the terms next to it.
A note on status. DwellTime is in early development and nothing here is live. Field names, levels, windows and reason classes describe the planned MVP and may change before a pilot. Where a term refers to something the product deliberately does not do, the entry says so plainly rather than leaving you to guess.
For how these terms fit together into three scores, read how DwellTime works.