[bù zhuó biān jì]
not to the point; (of a talk) empty and impracticable; entirely irrelevant in a roundabout way; far-fetched; far off the mark; irrelevant; neither here nor there; not touch the edge; off the point; totally beside the point; wide of the mark;
long rambling talk
不着边际的长篇大话
irrelevant talks
不着边际的话
The more he talked, the further he strayed from the point.
他越讲越不着边际。