What is a compound word?
A compound word is a word that is composed of two or more separate words that are combined to make a new word.
For example, combine dragon and fly to make the word dragonfly which has a completely different meaning than either of the original words.
One takes a root word, like the example "fly" and adds a descriptive word such as "dragon" to get dragonfly. In a related question, "treetop" applied.
A word with two parts (for example, butterfly is a compound word because is has butter and then fly) others could be:
paperclip, newsstand, newspaper, eyelid, bedrock, ladybug, pigtail, pigpen, flowerpot, handbag, bedtime, handshake, ect.
Bamboo is not a compound word. A compound word is essentially a word that is created by putting two independent words together, that could stand alone if you were to break the compound word into two. An example of a compound word is dragonfly, or bookworm! Since the word bamboo does not break into two words that can stand on their own, you can know that it is not a compound word.