糸口

彼の証言が事件解決の糸口となった。

His testimony provided the clue that led to solving the case.

初対面の相手と話の糸口を見つけるのは難しい。

It is hard to find a way to start a conversation with someone you have just met.

両国は交渉再開の糸口をつかめずにいる。

The two countries have been unable to find a starting point for resuming negotiations.

毛糸玉の糸口が見つからず、なかなか編み始められない。

I can't find the end of the yarn in the ball, so I can't get started knitting.

繭を湯で煮てから、糸口を引き出す。

After boiling the cocoon in hot water, you draw out the end of the thread.

絡まった糸は、まず糸口を探してから少しずつほどいていく。

With tangled thread, you first look for the end and then undo it little by little.