Challenging means demanding, in a way that tests you. A challenging climb, challenging conditions, challenging behaviour.
It is often a polite word for difficult, and in official language a challenging situation usually means a bad one. In care and education, challenging behaviour is a technical term for behaviour that puts somebody at risk, and it is deliberately neutral about blame.
1adjectivechallengingDemanding, in a way that tests you.
“Climbing the mountain was challenging, but the view made it worth it.”
challenging is a quality of difficulty.
Challenge plus -ing, from Old French chalenge, an accusation, from Latin calumnia, a false charge. Calumny is the same root.
Middle English
chalengynge
English, today
challenging
From Middle English chalengynge; equivalent to challenge + -ing.
Etymology from Wiktionary, CC BY-SA