If you mean a fluorescent lightbulb:
* Tube fluorescent: This is the most accurate translation, but it's a bit technical.
* Lampe fluorescente: This is a more general term for a fluorescent lamp.
* Néon: This is the most common word for fluorescent lighting in French, but it specifically refers to the long, thin, glass tubes that are filled with neon gas.
If you mean a streetlight:
* Réverbère: This is the most common word for a streetlight in French.
If you are referring to someone who is slow to understand (idiomatic meaning of "tubelight"):
* Lent d'esprit: This translates to "slow of mind" and is a common way to describe someone who is not quick to understand.
* Naïf: This means "naive" and can be used to describe someone who is easily fooled or misled.
* Simplet: This means "simpleton" and is a more informal way to describe someone who is not very bright.
It's important to consider the context and the specific meaning of "tubelight" before choosing a translation.