Wikipedia
Grand Cross is the highest class in many chivalric orders. Sometimes a holder of the highest class or grade are referred to as " Commander Grand Cross", " Knight Grand Cross" or just "Grand Cross"; in other cases the actual insignia is called the "grand cross".
Alternatively, in some other orders, the highest class may be called the "Grand Cordon", "Grand Collar", etc. In those cases, the rank of Grand Cross may come after another rank (e.g. the Portuguese Order of Saint James of the Sword).
In the United Kingdom, the rank entails admission to knighthood, allowing the recipient to use the title ' Sir' (male) or ' Dame' (female) before his or her name. This stands in contrast to the typical practice in other countries where knighthood is conferred at the initial, lowest rank of the order. The grand crosses of the various British orders are usually styled "Knight Grand Cross" or "Dame Grand Cross".
In astrology, a Grand Cross is said to occur when four planets are all separated from each other by Square aspects (90 degrees apart). A Grand Cross can also be viewed as two oppositions (180 degrees apart) separated from each other by a square. In a Grand Cross, there is one planet in each astrological element ( fire, earth, air and water) but all the planets are in signs of the same modality or quality.
Because all the aspects in a Grand Cross are considered difficult aspects, the Grand Cross is seen as a source of extreme tension whereby various aspects of the personality (represented by the planets) are working at cross purposes that serve to nullify each other. This pulls the native in many directions, ultimately leading to indecisiveness and an inability to produce concrete achievements. It is said to take extraordinary effort to overcome the conflicts in a Grand Cross.
An example of a Grand Cross would be with Saturn at 15° Virgo, Uranus at 15° Sagittarius, Neptune at 15° Gemini and Pluto at 15° Pisces. This is a mutable Grand Cross, which is said to be especially difficult with respect to the problem of maintaining focus in communication. A cardinal Grand Cross is said to cause a particular difficulty in accomplishing goals because the individual wants to accomplish everything at the same time: he/she usually ends up accomplishing very little (if anything at all). A fixed Grand Cross is said to lead to a person who is well organized but does not know where to direct their talents. Consequently, those with a fixed grand cross tend to be stuck in the same place.
People with many squares in their horoscope, however, if they work hard enough at overcoming the conflicts thus involved, are said to be able to achieve remarkable personal growth and self-fulfillment.
Usage examples of "grand cross".
A thanksgiving service was arranged, Kutuzov was awarded the Grand Cross of Maria Theresa, and the whole army received rewards.
It was that of a man, from five to eight and thirty, in the uniform of a general officer, wearing the double epaulet of heavy bullion, that indicates superior rank, the ribbon of the Legion of Honor around his neck, which showed he was a commander, and on the right breast, the star of a grand officer of the order of the Saviour, and on the left that of the grand cross of Charles III.
He was a veteran of the battles of Heligoland, Dogger Bank, and Jutland, and a recipient of the Grand Cross, the Order of Orange-Nassau of Holland, and the Russian Order of St.