Ingress and egress look and sound like they’re opposites, and they are. They’re primarily used in the context of entrances and exits, especially in architecture and other fields related to planning how people get in and out of places.
You can probably guess from the in in ingress that it generally means “the act of going in” or refers to an entryway. But there’s a lot more to know about these words and how exactly they’re used—including in astronomy and in terms like egress window. Join us as we get into the ins and outs of ingress and egress.
⚡ Quick summary
Ingress can refer to both the act of entering or to an entryway (an entrance) itself. Egress refers to both the act of exiting or to an exit itself. In astronomy, they’re used in a more specific way relating to heavenly bodies (like planets) entering into or emerging from an eclipse.
What does ingress mean?
Ingress means “the act of entering,” “the right of entering,” or “the means of entering.” The last sense is typically the one used in relation to architecture and related fields. A point of ingress in a building is an entryway. It’s a concise way of referring to a place where people can enter that avoids using a more specific term, like door (since points of ingress might not all technically be doors). The word isn’t always used in relation to buildings—it could be applied to parking lots, for example, which often have multiple points of ingress for vehicles to enter.
In astronomy, ingress is another word for immersion, the entrance of a heavenly body (such as a planet or a moon) into an eclipse caused by another heavenly body (like when the moon moves into Earth’s shadow) or into another instance of their paths crossing in some way (such as an occultation or a transit).
What does egress mean?
Egress means “the act of going out,” “the right to go out,” or “the means of going out.” The last sense is the one used in relation to architecture and related fields. For example, a fire safety code often requires a building to have multiple points of egress—places for people to exit, such as doors and fire escapes. A parking lot might have some one-way access points devoted to ingress and others devoted to egress.
In astronomy, egress is another word for emersion, the emergence or exit of a heavenly body from an eclipse, occultation, or transit—that is, when it comes back into view.
What is an egress window?
An egress window is a window or skylight that can serve as an exit in an emergency. They’re not intended to be regular means of access—they’re typically much smaller than doors, just big enough for a person to crawl through in case of something like a fire or a building collapse. You’ll especially see the term used in building codes and plans.
Where do ingress and egress come from?
The -gress part in both words ultimately comes from the Latin gradī, meaning “to go, step, walk”; this verb is also the origin of the word grade. The prefix in- means, yep, “in,” and the prefix e- is a variant of ex-, which means “out” and is also used to form the word exit.
What is the difference between ingress and egress?
The difference between ingress and egress might seem obvious: ingress refers to an entrance, and egress refers to an exit. And generally that’s true. Of course, it’s very common for many access points to be used for both ingress and egress—you come in the same door you go out. But in architecture and site planning, it’s often important to differentiate the two for many different reasons, such as accessibility, safety, and proper traffic flow.
Even though the words are used in more specific ways in astronomy, the basic idea is the same: ingress involves entering, and egress involves emerging or exiting.
Remember: ingress goes in and egress exits.
Examples of ingress and egress used in a sentence
Take a look at some example sentences to help you remember the difference between ingress and egress.
- The room has two points of egress, but only one point of ingress—one door is an emergency door that only opens outward.
- The developer plans to add another ingress point for the proposed neighborhood so that residents can enter from the south end.
- The investigation revealed that a broken door prevented egress.
- You’ll have to add an egress window to get the basement up to code.
- The moon began egress, exiting Earth’s shadow.
