# boundary

Pronunciation: US say "BOWN-duh-ree" /ˈbaʊndəɹi/; UK/AUS say "BOWN-dree" /ˈbaʊndɹi/

## Noun

1. A dividing line or place marking where one area ends and another begins.
   - Simple: A line that separates one area from another.
   - _Surveyors spent the morning marking the boundary between the two properties._
   - _A chain of mountains forms the boundary separating the two regions._
2. A limit marking off something nonphysical, such as your privacy, comfort zone, or professional role, from what lies beyond it.
   - Simple: A limit you set on what others can say or do to you.
   - _Therapists often help clients establish healthy boundaries with demanding relatives._
   - _He crossed a professional boundary by asking his coworker such personal questions._
3. An edge of the playing field, or the line that marks it.
   - Simple: The line that marks the outer edge of a sports field.
   - _The fielder chased the ball all the way to the boundary._
   - _A painted rope usually marks the boundary on a cricket ground._
4. In cricket, a scoring shot in which the ball reaches or clears the field's edge, earning the batting team four or six runs.
   - Simple: In cricket, a hit that sends the ball to the edge of the field, scoring four or six runs.
   - _She struck three boundaries in a single over._
   - _A late boundary off the final ball won the match._
5. In topology, the set of points lying in a set's closure but not in its interior.
   - Simple: In math, all the places at the very edge of a shape or group, between its inside and its outside.
   - _The boundary of an open disk is the circle that encloses it._
   - _Topologists often compute the boundary of a given subset._
6. In Philippine usage, the fixed sum a bus or jeepney driver pays the vehicle operator from the day's fares, with any excess kept as wages. *(Philippines)*
   - Simple: In the Philippines, the set fee a bus or jeepney driver pays the vehicle's owner, keeping the leftover fares as pay.
   - _Many jeepney drivers struggle to meet the daily boundary when passengers are few._
   - _The operator raised the boundary, leaving drivers with thinner earnings._

## Origin

Formed from "bound" plus the suffix "-ary," which traces back through Old French to Latin.

Source: DictionaryAI, https://dictionaryai.com/define/boundary (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).