ikinariyukinari
1.

Describes an event or action that occurs suddenly and unexpectedly, without any prior indication or preparation, often catching people off guard.

2.

Refers to a situation where something happens immediately at the beginning or onset, emphasizing a lack of gradual development or anticipation.

3.

Indicates a startling occurrence that takes one by surprise, highlighting the absence of any forewarning or prior context.

Example:

そのタクシーはいきなり左に曲がった。