anaphylaxis
Concise Oxford English Dictionary © 2008 Oxford University Press:
anaphylaxis /ˌanəfɪˈlaksɪs/
▶noun Medicine an extreme allergic reaction to an antigen to which the body has become hypersensitive following an earlier exposure.
– derivatives
anaphylactic adjective.
anaphylactic adjective.
– origin early 20th cent.: mod. L., from Gk ana- ‘again’ + phulaxis ‘guarding’.
'anaphylaxis' also found in these Oxford entries:

