feeling of vitality; sense of being alive
Refers to a palpable sense of life, energy, or aliveness, often used in descriptions of art, nature, or a person's presence.
His paintings are overflowing with a feeling of vitality.
This forest is full of a sense of being alive.
活気 is a more general term for liveliness or energy in a place or atmosphere, whereas 生命感 emphasizes a deeper, organic sense of life.
Compound of 生命 (せいめい, 'life') and 感 (かん, 'feeling, sense').