astronomical  
adjective uk/ˌæs.trəˈnɒm.ɪ.kəl/ us/ˌæs.trəˈnɑː.mɪ.kəl/
  (SCIENTIFIC)      
  [ before noun ]天文学的;天文的,天体的 
connected with astronomy
  the Royal Astronomical Society 皇家天文学会 
 astronomical observations/instruments 天文观测/仪器 
   (LARGE)      
 informal (also astronomic, /ˌæs.trəˈnɒm.ɪk/ /ˌæs.trəˈnɑː.mɪk/)极为巨大的;天文数字的 
An astronomical amount is extremely large.
  an astronomical rent/bill/price/fee 巨额租金/天文数字般的账单/天价/极高的收费 
 Synonyms: big (LARGE)colossalelephantine enormousgargantuangiant giganticginormous goodly great (BIG)heftyhugeimmensejumbolarge mahoosive mammoth massiveoutsizeoversize prodigious sizeable stupendousthumping tidy tremendousvastvoluminous walloping whopping