Not ideal
What it really means
A classic understatement for a bad situation. "Not ideal" can describe anything from a mild inconvenience to a disaster, said in the same calm voice.
Context, tips & common mistakes
British understatement compresses catastrophe into small words, and "not ideal" is its flagship: the train being cancelled is not ideal, and so is the kitchen being on fire. Fellow phrases — "a bit of a problem", "slight hiccup", "could have gone better" — run on the same exchange rate: multiply the stated severity several-fold to find the real one.
This matters most at work, where a British colleague's "we might have a slight issue with the deadline" can mean the deadline is dead. When you genuinely cannot tell, ask for the number: "on a scale of one to ten, how bad?" — asked with a smile, it is a recognised decoding move, not rudeness. Learn to transmit as well: announcing your own disasters as "slightly not ideal" earns the quiet appreciation Brits reserve for composure.
Example conversation
What you could say back
No spoken reply needed for this one.