departure, publish, emit, start from, disclose
發 centers on setting something into motion from a starting point: departing, emitting, publishing, or disclosing. Each sense is a way of sending something out or making it begin.
發 is the traditional form, later simplified to 発. It combines 癶 (footsteps outward) with 弓 (bow) and 殳 (action), suggesting shooting an arrow to start or send forth. The modern form 発 replaces the lower components with a simplified shape.
The top 癶 looks like two feet stepping out, and below are a bow 弓 and an action hand 殳. Imagine drawing a bow to shoot an arrow, launching it outward—this is departure, emission, or disclosure.
For ハツ, picture a hat flying off as you shoot the arrow: hat -> ハツ, and the arrow departs with a sudden motion.