bitterly

The story

1. Old English · inherited frombiterlīċe
2. Middle English · inherited frombitterli
3. English todaybitterly

From Middle English bitterli, biterli, biterliche, from Old English biterlīċe, bitterlīċe (“bitterly”), equivalent to bitter + -ly. Cognate with German Low German bitterlik (“bitterly”), German bitterlich (“bitterly”), Swedish bitterligen (“bitterly”).