Sentence:  Her mother wrote Kate of her grief at the death of Kate 's baby and at Jonathan 's decision to go with the South `` And , dear Kate '' , she wrote , `` poor Dr. Breckenridge 's son Robert is now organizing a militia company to go South , to his good <WSD>father</WSD> 's sorrow . 
Meaning of the word marked with <WSD> tags:  a male parent (also used as a term of address to your father)