満員

1. Origins, structure, and basic meaning

• Structure: 満員 (まんいん) is the state of all passenger or seat capacity being filled. It appears as a state and a change into it.
• Basic usage: A morning train is full of passengers; a venue reaches capacity and closes entry.

2. Common pitfalls and similar expressions

• Packed transport state and capacity threshold closing admission
  • Occupants appear as 乗客で; changing subject as 会場が. It means reaching human capacity, not merely being small.