- insanely or wildly: The old witch cackled madly.
- with desperate haste or intensity; furiously: They worked madly to repair the bridge.
- foolishly: They lived madly, wasting all their money.
- extremely: They’re madly in love.
- in an insane or foolish manner
- with great speed and energy
- informal extremely or excessivelyI love you madly
adv.early 13c., from mad (adj.) + -ly (2). Colloquial meaning “passionately” had emerged by 18c.