There are multiple definitions:

1. oral allergy syndrome(English)

   • Allergy

2. oligoadenylate synthetase(English)

   • widely distributed in Metazoa including sponges, fish, reptiles, birds and mammals and showing large variation, with one to twelve members in any given species. Upon double-stranded RNA binding, avian and mammalian types generate the second messenger 2'-5'-linked oligoadenylate (2-5A), which activates ribonuclease L and blocks viral replication
   • dsRNA, RNaseL
   • Virology
   • https://doi.org…2862-018-1315-x

3. Overt Aggression Scale(English)

   • for the objective rating of verbal and physical aggression
   • OAS-M
   • Behavior(al science), Scoring systems/scales, Psychiatry
   • https://doi.org…76/ajp.143.1.35