Abrupt; sudden; happening without warning or preparation (often used for remarks or changes of topic).
彼の話は唐突で、ついていけなかった。
His remarks were abrupt and I couldn't follow.
唐突な質問に答えに困った。
I was at a loss to answer the sudden question.
唐突に会いに来られても準備がない。
Even if you come to see me suddenly, I'm not prepared.
説明なく話題が唐突に変わった。
The topic changed abruptly with no explanation.