Direct Compounds:
* Brotherhood: A group of brothers or a feeling of fellowship among them.
* Brotherly: Resembling or characteristic of a brother, especially in showing kindness, affection, or loyalty.
* Brother-in-law: The brother of one's spouse.
* Brother-sister: Referring to a brother and sister.
* Brother-to-brother: Emphasizing a relationship between two brothers.
Phrases that function as Compound Nouns:
* Foster brother: A boy raised as a member of a family, but not biologically related.
* Stepbrother: A brother by marriage, resulting from a parent remarrying.
* Half-brother: A brother with only one parent in common.
* Fraternal brother: A twin brother (as opposed to an identical twin).
* Blood brother: Two men who have made a symbolic blood pact, signifying a strong bond.
Other Combinations:
* Big brother: An older brother, or a person or organization that acts as a protector or mentor.
* Little brother: A younger brother, or someone treated like a younger sibling.
* Brotherly love: Affection and loyalty shown between brothers.
Let me know if you'd like more examples or want to explore compound words with a different theme!