without advance notice; without warning
Used when something happens suddenly, without prior announcement or notification.
彼は予告なしに会社を辞めた。
He quit the company without advance notice.
予告なしに停電が起きた。
A power outage occurred without warning.
いきなり is more casual and often implies abruptness or lack of preparation, whereas 予告なしに is neutral and focuses on the absence of a formal notice.
Standard kanji spelling.
Variant with 無し instead of なし; slightly more formal or emphatic.
Compound of 予告 (advance notice) + なしに (without).