nounWord forms:  plural -di (-ˌdaɪ)1.   a technical name for slash (sense 12) 
2. a gold coin of the Byzantine empire
  Word origin
C14: from Late Latin 
solidus (
nummus) a gold coin (from 
solidus solid); in Medieval Latin, 
solidus referred to a shilling and was indicated by a long 
s, which ultimately became the virgule