подноготный

Etymology
From. The figurative senses refer to the medieval torture method of driving sharp objects under a suspect's fingernails to extract confessions.

Adjective

 * 1) under the fingernail
 * 2)  secret, hidden
 * 3)  perfectly frank, brutally honest; giving the lowdown on something
 * 4)  meticulous, thorough
 * 1)  perfectly frank, brutally honest; giving the lowdown on something
 * 2)  meticulous, thorough
 * 1)  meticulous, thorough
 * 1)  meticulous, thorough