Definition from Wiktionary, the free dictionary
- A conventional phrase used to start a letter or conversation or otherwise to acknowledge a person's arrival or presence.
It's polite to begin a letter with a greeting, but this practice is less common in email.
- (uncountable) The action of the verb to greet.
1898, Winston Churchill, chapter 2, in The Celebrity:
- I had occasion […] to make a somewhat long business trip to Chicago, and on my return […] I found Farrar awaiting me in the railway station. He smiled his wonted fraction by way of greeting, […], and finally leading me to his buggy, turned and drove out of town.
acknowledgement of a persons presence or arrival