This is the 2559th most frequent Russian word.
сложный
Complex; difficult.
The word 'сложный' is used to describe something that requires a lot of effort or is difficult to solve, showing that the task has a challenging nature.
Эта задача очень сложная.
This task is very complex.
Here, 'сложный' is applied to describe an intricate or multifaceted personality, implying that understanding or dealing with it is not straightforward.
У него сложный характер.
He has a complicated personality.
In this sentence, 'сложный' characterizes a challenging and perhaps problematic time, indicating emotional or situational difficulty.