日光灯

• 日(sun (pictograph))ASSOCIATIVE

The character 日 is drawn as a round sun with light rays inside.

• ⺌(small light radiating upward)ASSOCIATIVE
• 兀(standing person; upright person)ASSOCIATIVE

Light shining down from above a person standing upright creates the image of 光, meaning light.

• 火(fire)RADICAL
• 丁(nail; peg)PHONETIC

A lamp uses fire to shine brightly, and its sound reading is suggested by the component ding.