Literally: name / reputation – reality – one – body
Alternately: A thing is as it is said to be. The truth of a matter matches its reputation. Title and substance are as one. For example, when a famous storyteller really can captivate an audience, or when a man said to be an incompetent pathological narcissist turns out to actually be an incompetent pathological narcissist even after being given lots of power and responsibility, instead of magically “pivoting” into the dignity of the office.
Notes: There are several non-yojijukugo variants of this phrase, such as 名実共に (meijitsu tomo ni), “reputation and substance together” and 名実相伴う (meijitsu aitomonau), “reputation and substance accompany each other.”