komukomu
1.

To reach a state where a location is filled to capacity with people or things, making it difficult to move or take desired actions.

2.

To become complicated as elements intertwine or involve themselves in a convoluted manner.

3.

To indicate the act of thoroughly completing an action or process to the fullest extent.

4.

To remain in a specific state without returning easily to a normal condition, often implying a deep immersion in that state.

Example:

今晩は列車がとても込んでいる。