What it means
In the Jaimini chara-karaka ranking the Amatyakaraka is the planet at the second-highest degree within its sign - one step below the Atmakaraka. 'Amatya' means minister or counsellor: if the Atmakaraka is read as the king of the chart, the Amatyakaraka is the minister who carries out the king's agenda in the world.
How it is read
It is read for career and livelihood in the widest sense - not a job title, but the kind of work, counsel and resources through which the life's central theme gets executed. Practitioners weigh it alongside the 10th house and its lord, and the relationship between Atmakaraka and Amatyakaraka - by sign, aspect or dasha - is a classical ingredient in judging professional rise.
What to watch for
The same honesty applies as to every chara karaka: this is Jaimini, not Parashara, the seven-versus-eight-planet schemes disagree, and a degree ranking is only as reliable as the birth time behind it. Two planets close in degree can trade places with a small time correction, and the Amatyakaraka is the rank that swaps most often in practice.