deviation. 1  the act of deviating. 2  departure from a standard or norm. 3  Statistics. the difference between one of a set of values and some fixed value, usually the mean of the set. 4  Navigation. the error of a magnetic compass, as that of a ship, on a given heading as a result of local magnetism. 5  Optics.
The definition of an invitation is a request for a person's attendance at an event. An example of an invitation is a printed card asking family and friends to come to the sender's wedding. 1  an inviting to come somewhere or do something. 2  the message or note used in inviting.  enticement or allurement.
The technically correct word on wedding gifts, according to most etiquette experts, is that no one is required to give one. A wedding invitation is just that, an invitation to relatives and friends to join in the celebration. You won't need to bring a gift as the price of admission. If those who are invited feel moved to show their support and friendship with a gift, then the wedding couple should be grateful. Custom, however, is different.