حَمُوكَ: your male in-law.
جَاءَ حَمُوكَ، رَأَيْتُ حَمَاكَ، سَلَّمْتُ عَلَى حَمِيكَ.
Translation: Your male in-law came; I saw him; I greeted him.
هَنٌ is a classical euphemistic noun for a thing or a private part, depending on context. The textbook includes هَنُوكَ among the six.
هَنُوكَ — هَنَاكَ — هَنِيكَ
These illustrate the book's special inflectional pattern; other historical inflectional usages are also attested for this noun.
Note: The goal here is to learn the grammar, not to prioritize these uncommon words for everyday speech.