A dangerous atmosphere

In my Business English class this evening, the statement "You should keep your private life totally separate from your work" was being discussed and we were imagining various scenarios where this might certainly be considered true. All of my students are managers so we were considering one such scenario whereby two employees in the office are connected romantically and then break up. That would create a difficult atmosphere wouldn't it? I said.

険悪　said Mr. Ohta.

険 - ken - danger, steep
悪 - aku - bad
険悪 - kenaku = threatening, stormy, ominous...

What he was referring to, was perhaps 険悪なムード - a dangerous atmosphere . But this word has many uses:

険悪な天候　－　けんあくなてんこう　－　threatening weather
険悪な空　－　けんあくなそら　－　 a threatening sky
険悪な形相　－　けんあくなぎょうそう　－　a murderous look
険悪の相　－　けんあくのそう　－　a wild look or threatening aspect
険悪な顔つき - けんあくなかおつき　－ a black look
(人）に対して険悪な顔をする　－（ひと）にたいしてけんあくなかおをする　－ to give someone a filthy look

You can find heaps more examples on SPACEALC.