noun
beloved son; dear son
Polite, somewhat formal term used to refer to someone else's son, or occasionally one's own son in humble or affectionate contexts. Often used in letters or announcements.
ご愛息のご結婚、おめでとうございます。
Congratulations on your beloved son's marriage.
愛息の成長を温かく見守ってまいりました。
We have warmly watched over our dear son's growth.