ornithologist

UK: /ˌɔː^rnɪˈθɒlədʒɪst/

WordReference Random House Learner's Dictionary of American English © 2025

or•ni•thol•o•gy /ˌɔrnəˈθɑlədʒi/   n. [uncountable]

1. Biology the branch of zoology that deals with birds.

or•ni•thol•o•gist, n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2025

or•ni•thol•o•gy  (ôr′nə thol′ə jē), n. 

1. Biology the branch of zoology that deals with birds.

• Neo-Latin ornithologia. See ornitho-, -logy
• 1645–55;

or•ni•tho•log•i•cal  (ôr′nə thə loj′i kəl), or′ni•tho•log′ic, adj.  or′ni•tho•log′i•cal•ly, adv. 
or′ni•thol′o•gst, n.