I. ˈsə-d ə n adjective
Etymology: Middle English sodain, from Anglo-French sudain, from Latin subitaneus, from subitus sudden, from past participle of subire to come up, from sub- up + ire to go — more at sub- , issue
Date: 14th century
1.
a. : happening or coming unexpectedly
a sudden shower
b. : changing angle or character all at once
a sudden drop in the ocean bottom
2. : marked by or manifesting abruptness or haste
a sudden departure
3. : made or brought about in a short time : prompt
Synonyms: see precipitate
• sud·den·ly adverb
• sud·den·ness ˈsə-d ə n-(n)əs noun
II. noun
Date: 1558
obsolete : an unexpected occurrence : emergency
•
- all of a sudden