Invite

v. request the presence of; solicit, politely request; attract; encourage, provoke, promote

An invitation system (or invite system) is one method of website registration. Unlike open registration, where all users can join, and closed registration, where there is a moratorium on new users joining, invites allow current users to select who can join, while allowing site administrators to maintain a stronghold on the population of the service.
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Noun
1. a colloquial expression for invitation; "he didn't get no invite to the party"
(hypernym) invitation
(derivation) pay for
Verb
1. increase the likelihood of; "ask for trouble"; "invite criticism"
(synonym) ask for
(hypernym) arouse, elicit, enkindle, kindle, evoke, fire, raise, provoke
(derivation) invitation
2. invite someone to one's house; "Can I invite you for dinner on Sunday night?"
(synonym) ask over, ask round
(hypernym) request, bespeak, call for, quest
(verb-group) ask in
3. give rise to a desire by being attractive or inviting; "the window displays tempted the shoppers"
(synonym) tempt
(hypernym) stimulate, shake, shake up, excite, stir
(derivation) invitation
4. ask someone in a friendly way to do something
(synonym) bid
(hypernym) request
(hyponym) tempt, allure
(derivation) invitation
5. have as a guest; "I invited them to a restaurant"
(synonym) pay for
(hypernym) interact
(see-also) ask out, invite out, take out
6. ask to enter; "We invited the neighbors in for a cup of coffee"
(synonym) ask in
(hypernym) request, bespeak, call for, quest
(hyponym) call in
(verb-group) ask over, ask round
(derivation) invitation
7. request the participation or presence of; "The organizers invite submissions of papers for the conference"
(synonym) call for
(hypernym) request, bespeak, call for, quest
(verb-group) request, bespeak, call for, quest
(derivation) invitation
8. express willingness to have in one's home or environs; "The community warmly received the refugees"
(synonym) receive, take in
(hyponym) welcome
(derivation) invitation

n. guest, visitor

v. invite, summon; ask, bid

v. invite, request the presence of; solicit, politely request