The apparent dip $\delta'$ is the angle of dip observed when the dip circle is not oriented in the magnetic meridian (tilted at angle $\phi$ from the meridian).

The relationship is: $\tan\delta' = \frac{\tan\delta}{\cos\phi}$, where $\delta$ is the true dip.

Since $\cos\phi \leq 1$: $\tan\delta' \geq \tan\delta$, so $\delta' \geq \delta$.

Therefore true dip is always less than or equal to apparent dip. They are equal only when $\phi = 0°$ (dip circle in the meridian).