Refers to a rough overview or the main points of a story, plan, or explanation. Often used in formal or explanatory contexts.
事件のあらましを説明してください。
Please explain the outline of the incident.
Adverbial use indicating an approximate amount or degree. Less common than the noun sense; often replaced by だいたい or およそ in casual speech.
仕事はあらまし終わった。
The work is roughly finished.