(a word of kindly greeting, as to one whose arrival gives pleasure): Welcome, stranger!
–noun
2.
a kindly greeting or reception, as to one whose arrival gives pleasure: to give someone a warm welcome.
–verb (used with object)
3.
to greet the arrival of (a person, guests, etc.) with pleasure or kindly courtesy.
4.
to receive or accept with pleasure; regard as pleasant or good: to welcome a change.
5.
to meet, accept, or receive (an action, challenge, person, etc.) in a specified, esp. unfriendly, manner: They welcomed him with hisses and catcalls.
–adjective
6.
gladly received, as one whose arrival gives pleasure: a welcome visitor.
7.
agreeable, as something arriving, occurring, or experienced: a welcome rest.
8.
given full right by the cordial consent of others: She is welcome to try it.
9.
without obligation for the courtesy or favor received (used as a conventional response to expressions of thanks): You're quite welcome.
—Idiom
10.
wear out one's welcome, to make one's visits so frequent or of such long duration that they become offensive: Your cousins have long since worn out their welcome.
Origin: bef. 900; ME < Scand; cf. ON velkominn, equiv. to velwell1+ kominncome(ptp.); r. OE wilcuma one who is welcome, equiv. to wil- welcome (see will2) + cuma comer
Received with pleasure and hospitality into one's company or home: a welcome guest.
Giving pleasure or satisfaction; agreeable or gratifying: a welcome respite from hard work.
Cordially or willingly permitted or invited: You are welcome to join us.
Used in the expression you're welcome to acknowledge an expression of gratitude.
n.
A cordial greeting or hospitable reception given to an arriving person.
A reception upon arrival: gave the stranger an unfriendly welcome.
The state of being welcome: Don't overstay your welcome.
tr.v.
wel·comed, wel·com·ing, wel·comes
To greet, receive, or entertain (another or others) cordially or hospitably.
To receive or accept gladly: would welcome a little privacy.
interj. Used to greet cordially a visitor or recent arrival.
[Middle English, alteration (influenced by wel, well) of Old English wilcuma, welcome guest, welcome; see gwā- in Indo-European roots.] wel'come·ly adv., wel'come·ness n., wel'com·er n.
[wel-kuh
m] 
interjection, noun, verb, -comed, -com⋅ing, adjective