This is the 353rd most frequent Hungarian word.
működő
Functioning; operational.
The word 'működő' is used as an adjective to describe the machine (gép) as being operational or functioning.
A működő gép zajos.
The working machine is noisy.
Here, 'működő' modifies 'rendszert' (system), indicating that it is in operational condition and was subject to testing.
Ezt a működő rendszert tesztelték.
They tested this functioning system.
In this case, 'működő' describes 'megoldást' (solution), implying that the solution is viable and capable of working effectively.