Explanation:

- Fluorescent: This word refers to a bright or glowing light, usually created through the process of fluorescence, where a substance emits light upon absorbing radiation.

- Option 1: Elaborate - This means detailed or intricate. It doesn't relate to brightness or glowing.

- Option 2: Flowery - This usually describes something ornate or excessively elaborate in style. It doesn't mean glowing or emitting light.

- Option 3: Perfumed - This indicates something has a pleasant scent. It's unrelated to light or glow.

- Option 4: Glowing - This means emitting a steady light or bright in appearance.

- Glowing is the most appropriate synonym for fluorescent, as it aligns with the idea of light emission.