to put to use; to apply; practical; applied (science, linguistics etc)
应 (Yīng) · 7 strokes
Simplified form of 應. Phonosemantic compound. 心 represents the meaning and 䧹 represents the sound.
用 (yòng) · 5 strokes
Depicts a bucket with a handle on the right side. Based on the original meaning "bucket". The meaning of this character has shifted over time and now means "use".