IPA: //vɛkˈsɪl.ə.lɒdʒ.ɪst//
KK: /vɛkˈsɪl.ə.lɒdʒ.ɪst/
A person who studies or specializes in flags and their history, design, and symbolism.
The vexillologist presented a fascinating lecture on the flags of different countries.
Vexillologist → It is formed from "vexillum" (from Latin, meaning flag or banner) and "-logist" (from Greek "logistēs", meaning one who studies). A vexillologist is someone who studies flags and banners.
Think of 'vexillum' as a flag and '-logist' as someone who studies — so a vexillologist is a person who studies flags.