Knight of Pentacles
Upright
Utility, serviceableness, interest, responsibility, rectitude—all on the normal and external plane.
Reversed
inertia, idleness, repose of that kind, stagnation; also placidity, discouragement, carelessness.
A. E. Waite, The Pictorial Key to the Tarot (1911), Part III §2The picture
He rides a slow, enduring, heavy horse, to which his own aspect corresponds. He exhibits his symbol, but does not look therein.
Older readings
An useful man; useful discoveries. Reversed: A brave man out of employment.
A. E. Waite, The Pictorial Key to the Tarot (1911), Part III §4. Waite collected these and says they often disagree with the main meanings.Waite wrote in 1911 and some of his meanings show it. Tarot is a tradition of reflection, not a prediction, and no card decides anything for you.