1Honorific/polite prefix attached before a noun (or sometimes a verb stem) to mark respect or politeness — ご家族 ('your family'), ご利用 ('your use of ...'), ご質問 ('your question'). Mostly attaches to Sino-Japanese (on-yomi) words; native-Japanese words usually take お instead. A core building block of polite speech, from everyday courtesy to formal business style. Almost always written in kana as ご.
ご家族の皆様によろしくお伝えください。
Please give my regards to your family.
ご利用ありがとうございます。次回もぜひお待ちしています。
Thank you for your patronage. We look forward to seeing you again.
何かご質問があれば、ご遠慮なくおっしゃってください。
If you have any questions, please don't hesitate to ask.
ご連絡お待ちしております。
I look forward to hearing from you.
ご飯の前に手を洗いましょう。
Let's wash our hands before the meal.
2Honorific suffix on a noun referring to a person — 親御 (おやご, 'someone else's parents', respectful), 殿御 (とのご, archaic for 'master / husband'). In modern usage 親御さん is essentially the only living form; the rest sounds old-fashioned.
明日、子どもの親御さんと面談があります。
Tomorrow I have a meeting with the children's parents.
亡くなった親御さんのことを思うと、胸が痛む。
It pains me to think about her late parents.
昔の物語に出てくる「殿御」は、夫や主人を指す古風な呼び方だ。
The 殿御 (tono-go) seen in old tales is an old-fashioned word for a husband or master.