Pell-mell (usually hyphenated, but sometimes spelled pellmell) works (1) as an adverb meaning in a confused or reckless manner, and (2) as an adjective meaning confused or disordered in action. The English word comes from the French pêle-mêle. The French word is nearly a millennium old, and its exact origins are mysterious—though the second syllable is likely related to the verb mesler, which means to mix.
Examples
All has been happening pell-mell and no one seems to have an answer. [Salem News]
In distressing times like today, abandoning equities in a pell-mell dash for safety can wreak havoc on a sound investment plan. [Financial Post]
And if it keeps up its current rate of double-digit, pell-mell growth, it will surpass the US as the world’s largest economy by 2020. [Telegraph]
The White House has said repeatedly that it has not ruled out arming the rebels, who have retreated pell-mell this week. [Stuff.co.nz]