ラジオのボリュームを下げてください。

radio

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

volume (sound level); volume (books); volume; substantial quantity (e.g. hearty meal); bulk; bulkiness; mass; any kind of adjustment knob, not necessarily for sound

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to hang; to suspend; to wear (e.g. decoration); to lower; to reduce; to bring down; to demote; to move back; to pull back; to clear (plates); to remove (food, etc. from table or altar)

to give; to confer; to bestow; to kindly do for one; to oblige; to favour; to favor