I. ˈprī-ˌän noun
Etymology: New Latin, from Greek priōn saw, from priein to saw; from its sawlike bill
Date: 1848
: any of several small petrels (genus Pachyptila of the family Procellariidae) of the southern hemisphere that are bluish gray above and white below
II. ˈprē-ˌän noun
Etymology: pr oteinaceous + i nfectious + -on (II)
Date: 1982
: a protein particle that lacks nucleic acid and has been implicated as the cause of various neurodegenerative diseases (as bovine spongiform encephalopathy and Creutzfeldt-Jakob disease)