IPA: /ˈbʊkər/
KK: /ˈbʊkər/
A person who arranges or makes reservations, often for events, travel, or accommodations.
The booker secured a great deal for our hotel stay during the conference.
The word 'booker' originates from the Old English 'bōc' (meaning book) combined with the agent suffix '-er' (meaning a person who). A booker is therefore a person who deals with books or bookings.
Think of someone who is a 'person' ('-er') associated with 'books' ('bōc') — that's why a booker is someone who handles books or reservations.