{adj. phr.} 1. Thoroughly decayed or spoiled. * /This apple is inedible; it is brown and soft and rotten to the core./ 2. In total moral collapse. * /The Communist government of Cuba is rotten to the core./
ROTTEN TO THE CORE
Meaning of ROTTEN TO THE CORE in English
Dictionary of English idioms . Словарь английских идиом. 2012