truth, reality
實 centers on what is solid and genuine: truth and reality as opposed to falsehood or appearance.
實 is the older form of modern 実. It combines 宀 (roof) with 貫 (pierce/string together), suggesting something solid and filled under a roof, which extended to truth and reality.
Under a roof 宀, a string of coins 貫 represents something tangible and real. Truth is solid like a full purse.
For ジツ, imagine a judge hitting a gavel and declaring the truth: the sharp sound 'jitsu!' cues ジツ, and the courtroom scene reinforces reality.