A doorway is the opening in a wall where a door is installed, or the space you pass through when entering or leaving a room or building. When you walk from your classroom into the hallway, you step through a doorway. The doorway itself is the frame and opening, whether or not an actual door is attached.

Doorways connect spaces and mark transitions and boundaries. When a teacher stands in the doorway greeting students, she's positioned right at the threshold between inside and outside. In old castles, doorways were designed narrow and low to make them easier to defend. In modern homes, doorways in main living areas are often left open and wide to make spaces feel connected.

People use doorway in figurative ways too. You might hear someone describe an opportunity as “a doorway to new possibilities” because doorways represent passages from one state to another. Learning to read opens a doorway to knowledge. Mastering a difficult skill can be the doorway to a new career.

The word can also describe someone's position: if you're standing in the doorway, you're occupying that transitional space, not quite in one room or the other.