Overnight (adverb)

1. During or for the duration of the night.
2. During or for the length of a single night and the following day.
3. Happening suddenly or unexpectedly.

Origin:

From over- + night, meaning 'during the course of a single night'.

Examples:

1. We decided to stay overnight in the hotel and continue our journey in the morning.
2. The package will be shipped overnight and should arrive by 10am tomorrow.
3. The company experienced an overnight surge in popularity after a viral video was shared on social media.