also: たんちょ
noun
start; beginning; clue; first step
Refers to the very beginning or a hint that leads to understanding something; often used in formal or written contexts.
事件解決の端緒をつかんだ。
We found a clue to solving the case.
研究の端緒
The beginning of the research started from a small question.
端 (edge, beginning) + 緒 (thread, beginning). The combination suggests the 'thread' that leads to the start of something.