the.com/rung
A single step you stand on while pretending the ladder isn't wobbling.
means A horizontal bar on a ladder or chair used as a step or support, or figuratively a level in a hierarchy.
from From Old English hrung, a crossbar or rod, kin to words for staff and pole across the old Germanic tongues.
Career ladderMetaphorical rungs date to the 1800s.
Not a ringIdentical to past tense of ring, unrelated.
Chair anatomyThose bars between chair legs are rungs too.