1. interjection /ˈwɛl.kəm/
Greeting given upon someone’s arrival.
2. verb /ˈwɛl.kəm/
We welcome suggestions for improvement.
b) to accept something willingly or gladly.
3. adjective /ˈwɛl.kəm/
4. noun /ˈwɛl.kəm/
b) The utterance of such a greeting.
Wikipedia foundation.