Here in Hawaii, Shingon Mission temples are often called as "O-Daishi-san" which literally means "The Grand Master." Because the founder of Shingon School has been so well known as "Kobou Daishi", people affectionately call him "O-Daishi-sama (san)" and then later it came to mean a Shingon temple, too.
However, the word "Daishi" is actually not a proper noun. It is an honorary posthouse title given to virtuous priest by the Emperor. This custom to honor great priests was started in China and together with Buddhism, Daishi Title was brought to Japan. In 866, Saicho and Ennin of Tendai School received the first "Daishi" title from Emperor Seiwa. The title of "Dengyo Daishi" was given to Saicho who founded Japanese Tendai School, and "Jikaku Daishi" was given to Ennin.
Since then till today in the history of Japan, 33 titles were given to the distinguished priests who were mostly founders of new Buddhist schools in Japan. Among 33 titles, Honen Shonin has received 8 posthumous titles by eight different Emperors, starting from 1696. His first Grand Master Title was "Enko Daishi" given by Emperor Higashiyama. Then since 1711, Honen Shonin continue to receive "Daishigo" or Grand Master Title every 50 years together with Grand Memorial Service, called "Dai-Onki."
I assume one of the reasons why Honen Shonin alone received so many titles, can be from the political reason that Jodo shu was greatly supported and protected by the family of Shogun Tokugawa.
However, this never deny the significance of our founder. Rather he is definitely worth having 8 grand titles since Honen Shoin was a teacher of many other great teachers. He influenced many other priests who later founded new schools.
Interestingly 8 titles captured what was Honen Shonin like and his great accomplishments. So I feel very meaningful to introduce the literal meanings of Master Honen's Titles as follows.
Enko （円光） means "round light." "Round" indicates Honen's character who was always gentle and kind.
Tozen (東漸) literally means "Gradually moving East" which indicates a manifestation of Buddhism is transmitting to the Eastward.
Ejo (慧成）literally means "to complete wisdom." Honen Shonin was one of the most wise men in the history of human being because he reached the ultimate wisdom of ignorance.
Kokaku (弘覚）literally means "to spread the Enlightenment widely."
For Honen Shonin's achievement of enlightenment was to abandon pursuing enlightenement in this world. He forcussed to teach the way to Jodo (Pure Land.)
Jikyo (慈教）literally means "compassionate teaching." His teachings and words were full of compassion.
Meisho (明照）literally means "bright illumination." This title was given in 1911 by Emperor Meiji when Jodoshu celebrated 700th Grand Memorial for Honen Shonin. Here in Hawaii, this word "Meisho" is familiar and used such as "Meisho YBA", "Meisho Fujinkai." It indicates these organization was named after the new title "Meisho" in 1911, to commemorate it.
Wajun (和順）literally means "to follow peace." In a sense, Honen Shonin's teaching is to pursue the ultimate peace.
Houni Daishi (法爾）literally means "Just like Dharma." The name Honen was actually taken from the saying, "Jinen Houni" meaning, "Dharma naturally appear." It is said that his Master, Eikuu was so impressed to know young Honen was truly seeking for the truth.
Today, January 25th is a memorial day for our founder Honen Shonin who passed away 805 years ago. Although I do have a service every day, but I will take time for reciting Nembutsu in appreciation of our Master Honen.
The following is a list of Grand Master Title in Japan (Daishi-go). I've made this list based upon the _大師（僧） at Wikipedia (There was only Japanese information.) In case you found a mistake, please let me know.
1697 Honen (Enko Daishi by Emperor Higashiyama ) 法然/円光大師
1707 Shobou (Rigen Daishi by Emperor Higashiyama) 聖宝/理源大師
1711 Honen ( Tozen Daishi by Emperor Nakamikado) 法然/東漸大師
1761 Honen (Ejo Daishi by Emperor Momozono) 法然/慧成大師
1811 Honen (Kokaku Daishi by Emperor Kokaku)法然/弘覚大師
1861 Honen (Jikyo Daishi by Emperor Komei) 法然/慈教大師
1879 Dougen (Joyou Daishi by Emperor Meiji ) 道元/承陽大師
1882 Rennyo (Etou Daishi by Emperor Meiji）蓮如/慧燈大師
1883 Shinsei (Jisho Daishi by Emperor Meiji ) 真盛/慈摂大師
1883 Shunjo (Gachirin Daishi by Emperor Meiji )俊じょう/月輪大師
1909 Kanzan Egen ( Musou Daishi by Emperor Meiji) 関山慧玄/無相大師
1909 KeizanJokin (Josai Daishi by Emperor Meiji) 瑩山紹瑾/常済大師
1911 Honen (Meisho Daishi by Emperor Meiji )法然/明照大師
1917 Ingen(Shinku Daishi by Emperor Taisho) 隠元/真空大師 Obaku
1922 Nichiren (Rissho Daishi by Emperor Taisho) 日蓮/立正大師
1927 JuouSouhitsu (Bimyo Daishi by Emperor Showa )授翁宗弼/微妙大師
1938 MumonGensen (Enmyo Daishi by Emperor Showa )無文元選/圓明大師
1940 Ippen (Shojou Daishi by Emperor Showa ) 一遍/証誠大師
1961 Honen (Wajun Daishi by Emperor Showa ) 法然/和順大師
1972 Ingen (Kakou Daishi by Emperor Showa ) 隠元/華光大師
2011 Honen (Houni Daishi by Emperor Kinjo ) 法然/法爾大師
The following is a list of riests who have Daishig-o Title by sects
Saicho / Dengyo Daishi (766-822)
Ennin / Jikaku Daishi (7942-864)
Ryogen / Jiei Daishi ( 912-985)
Enchin / Chisho Daishi ( 814-891)
Shinsei / Jisho Daishi (1443-1495)
Tenkai / Jigen Daishi (1536-1643)
Kukai / Koubou Daishi (774-835)
Jitsuei / Doukou Daishi (786-847)
Shinga / Houkou Daishi (801-879)
Ekishin / Hongaku Daishi (827-906)
Shobou / Rigen Daishi ( 832-909)
Kakuban /Kougyo Daishi (1095-1143)
Shunjo /Gachirin Daishi (1166-1227)
Ryonin / Shoou Daishi (1073-1132)
Honen-bo Genku (1133-1212) 8 Daishigo Title
Shinran / Kenshin Daishi (1173-1262)
Rennyo / Etou Daishi (1415-1499)
Ippen / Shojo Daishi (1239-1289)
Kanzan Egen / Musou Daishi (1277-1360)
Juou Sohitsu / Bimyo Daishi (1296-1380)
Mumon Gensen / Enmyo Daishi (1323-1390)
Dougen / Joyou Daishi (1200-1253)
Keizan Jokin / Josai Daishi (1268-1325)
Shinku Daishi / Kakou Daishi)
Nichiren / Rissho Daishi (1222-1282)