[HedgeYourBets]

soap - savukkaaram. In some parts of rural TN, it is called "araippukkattai" (araippu being the ground paste people used to use before soap).

shampoo - I've been told the correct word is savukkaarakkuzhampu. My grandmother used to call it ciykkay thiravam - which is technically speaking incorrect since shampoo has nothing to do with the soap-nut, but still makes sense.

tubelight - I have heard "curaiviLakku" used colloquially. I don't know if it's "official" terminology, though.

binded book - "thaittha putthakam", I suppose. In what context would you want to use the phrase?

hardcover - I would use "thuNi attai" and "kagidha attai" for "hardcover" and "paperback", but there are probably better words. Does anyone know?