Longman Dictionary of Contemporary English - invitation

~ n 1 a written or spoken request to someone, inviting them to go somewhere or do something  (Did you get an invitation to the party?) invitation to do sth  (Shortly afterwards, Dawson received an invitation to speak at a scientific conference. | accept an invitation)  (President Yeltsin has accepted an invitation to visit the White House in June. | decline an invitation formal (=to not accept an invitation) | by invitation only (=only those people who have been invited can attend)) 2 a card inviting someone to attend a party, wedding etc  (Have you sent out all the wedding invitations yet?) 3 without invitation without having been invited  (They were always dropping by to visit, usually without invitation.) 4 encouragement to do something  (take sth as an invitation to do sth)  (He seemed to take my silence as an invitation to talk.) 5 at sb's invitation also at the invitation of sb if you go somewhere or do something at someone's invitation, you go there or do it because they have invited you to 6 open/standing invitation an invitation to do something, especially to visit someone, at any time you like  (My cousin Diana is living in China, and I have an open invitation to visit her.) 7 be an open invitation for/to sb to make it very easy for someone to rob you or harm you  (Leaving the car unlocked like that is just an open invitation to thieves.)