To greet someone in a friendly way when they arrive, or to receive them gladly.
The host welcomed us at the door.
They welcomed her to the team.
Welcome is followed directly by a person: “They welcomed us,” not “They welcomed to us.”
Common phrases & grammar
warmly welcome someone · welcome guests · welcome visitors · welcome someone to the team
[subject] welcome(s) [person] to [place or group]
[subject] welcome(s) [person] with open arms