deeply moved; even more emotional
A somewhat literary set phrase meaning one's emotion is heightened or felt more deeply than before, often used in reflective or narrative contexts.
Visiting my hometown after a long time, I was deeply moved.
Listening to his speech, I felt even more emotional.
感慨無量 means 'deep emotion' or 'profound feeling', while 感慨一入 emphasizes that the emotion is felt even more deeply than before or than expected.
一入 originally denoted one dipping in a dye bath, which deepens a fabric’s color. Figuratively, 感慨一入 describes an emotion made still deeper or more intense.