To Appoint
To Assign, To Designate, To Specify
する verb, transitive verb
When you determine and use your finger to point at someone or something, you're going to appoint them. Just imagine yourself determining who's the best for the job then pointing with your finger. That is who you will appoint. The する on the end makes it a verb, so 指定 would be "appointment" or "designation" or something along those lines. Cool how する works.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
ミーティングの場所は、お客さまが指定しました。
The meeting place was designated by the client.
自分でフライトを指定してもいいですか？
May I assign my own flight?
この絵は日本に国宝に指定されてます。
This painting is designated as a national treasure in Japan.