ladder
noun
steps consisting of two parallel members connected by rungs; for climbing up or down
ascending stages by which somebody or something can progress
“he climbed the career ladder”
a row of unravelled stitches
“she got a run in her stocking”
verb
come unraveled or undone as if by snagging
“Her nylons were running”
Synonymsrun
Source: WordNet 3.1, Princeton University