(いったん)

いったん
noun
one end; a part
See also: 一旦(いったん) (once, temporarily (一旦))
1. one end, one side
One end or extremity of a physical object such as a rope, road, or line.
I tied one end of the rope to a tree.
I could see the other bank from one end of the bridge.
(せん)一端(いったん)Aもう一端(いったん)B接続(せつぞく)してください
Connect one end of the cable to A and the other end to B.
2. a part, a glimpse, one aspect
A portion or fragment of something larger, often used to describe catching a glimpse of someone's character, ability, or a situation.
I got a glimpse of her talent.
This work expresses a part of his anguish.
事件(じけん)一端(いったん)(にな)っていたこと(あき)らかになった。
It became clear that he had played a part in the incident.

Usage: The two senses have different usage patterns.

Sense 1 (one end): Used for physical objects with two ends.

Sense 2 (a part/glimpse): Used with abstract nouns to mean "a part of" or "a glimpse of."

Note: Do not confuse with 一旦(いったん) (once, temporarily), which is an adverb with a completely different meaning.