The adv suddenly has 3 senses (first 3 from tagged texts)
1. (65) suddenly, all of a sudden, of a sudden -- (happening unexpectedly; "suddenly she felt a sharp pain in her side")
2. (42) abruptly, suddenly, short, dead -- (quickly and without warning; "he stopped suddenly")
3. (2) on the spur of the moment, suddenly -- (on impulse; without premeditation; "he decided to go to Chicago on the spur of the moment"; "he made up his mind suddenly")