Etymology From slap + dash. First attested in the late 17th century, meaning "careless".
1
Produced or carried out hastily; haphazard; careless.
They had seen Poland, and that was the sort of slovenly, slapdash place they were used to, but once across the German frontier they found everything—crops, roads, buildings—uncannily different.1989, Aleksandr Solzhenitsyn, translated by H. T. Willetts, August 1914, Farrar, Straus and Giroux, →ISBN, page 114:
When you're in the front entrance, get a feel for what's going on. Tours are never timed to coincide with breaks but if there are any children milling about, see what they're up to. If they're on a dutiful errand, for example delivering registers, the school probably encourages a responsible attitude. If they're play-fighting in the corridor without consequence, it tells a less impressive story and could mean a slapdash approach to discipline.2014 September 23, A teacher, “Choosing a primary school: a teacher's guide for parents”, in The Guardian:
1 more example
Valérie Pisano, the chief executive of Mila – the Quebec Artificial Intelligence Institute – said the slapdash approach to safety in AI systems would not be tolerated in any other field.2023 May 2, Josh Taylor, Alex Hern, “‘Godfather of AI’ Geoffrey Hinton quits Google and warns over dangers of misinformation”, in The Guardian, →ISSN:
Etymology From slap + dash. First attested in the late 17th century, meaning "careless".
1
In a hasty or careless manner.
2
Directly, right there; slap-bang.
Van Eyck signed his portrait of the Arnolfinis slapdash in the center of the painting.
3
With a slap; all at once; slap.
And yet, slap dash, is all again In every sinew, nerve, and vein; Runs here and there, like Hamlet's ghost1718, Mat[thew] Prior, “Alma: Or, The Progress of the Mind”, in Poems on Several Occasions, London: […] Jacob Tonson […], and John Barber […], →OCLC: