knurl (noun) hump: swelling, projection
Sinonime: absorbed, at work,
committed, connected with, dealing in,
deep,
doing,
employed,
engrossed,
immersed, in place, in use,
intent,
interested,
involved, occupied,
performing, practicing,
preoccupied,
pursuing,
rapt, signed, tied up,
unavailable,
working, wrapped up
Antonime: disengaged, inoperable, not working