### Clue: Get rich fast following work with upper class (7)
### Answer: OPULENT 
 ### Explanation: Definition: rich
 LENT(the fast observed by Christians before Easter) **placed after**(following, in an across clue) [ OP(abbrev. for "opus", an artistic work, say, of music or literature) **plus**(with) U(characteristic of or appropriate to the upper social classes) ].  Got held up trying to fit "get" into the definition.