ℚ
Definition from Wiktionary, the free dictionary
Character  ℚ  

Unicode name  DOUBLESTRUCK CAPITAL Q  
Unicode block  Letterlike Symbols  
Codepoint  U+211A  

See also: Appendix:Variations of "q"
Translingual[edit]
Etymology[edit]
From the initial of Italian quoziente (“quotient”), notation proposed in 1895 by mathematician Guiseppe Peano.
Symbol[edit]
ℚ
 (mathematics) The set of rational numbers.