Meaning of the word "pell mell" in English

What does "pell mell" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

pell mell

US /ˌpelˈmel/
UK /ˌpelˈmel/

Adverb

in a confused, disordered, or headlong manner

Example:
The crowd ran pell-mell out of the burning building.
Books were stacked pell-mell on the shelves.