Pronunciation: [bˈʊk ˈʌp] (IPA) 
The spelling of the phrasal verb "book up" consists of two words: "book" and "up". The first word is spelled /bʊk/, with the vowel sound represented by the symbol /ʊ/ as in "put". The second word is spelled /ʌp/, with the vowel sound represented by the symbol /ʌ/ as in "cup". Together, these two words form the verb "book up", which means to make a reservation or to fully reserve a space, such as a hotel room or a concert ticket.
Book up is a phrasal verb that has multiple meanings depending on the context. It is generally used informally and can be used transitively or intransitively.
When used transitively, book up means to reserve or make a reservation for something, typically an appointment, a hotel room, or a ticket. For example, one might say, "I booked up a table at the restaurant for tonight," indicating that they made a reservation for a table at the restaurant. Similarly, someone could say, "I booked up my flight to New York," meaning they made a reservation for a flight to New York.
In an intransitive sense, book up means to become fully booked or occupied. It refers to a situation where all available slots or spaces are taken or spoken for. For instance, if a hotel is fully booked, it means all the rooms have been reserved or occupied. Likewise, a concert or event can be booked up if all the tickets have been sold. This phrase is commonly used in the hospitality and entertainment industries to indicate a state of high demand or limited availability.
Overall, book up refers to the act of reserving or making a reservation, as well as the state of being fully booked or occupied. It signifies the process of securing or filling available slots, spaces, or tickets, depending on the context in which it is used.
The term "book up" is a phrasal verb made up of the verb "book" and the adverb "up". The etymology of "book" can be traced back to the Old English term "bōc", which referred to a written document or manuscript. It has cognates in various Germanic languages, suggesting a common Germanic root. The word "up" derives from Old English "ūp", which denoted elevation or a higher position. In combination, the phrase "book up" means to reserve or arrange a place, activity, or service in advance, often applied to booking or scheduling appointments, tickets, hotel rooms, or other similar tasks. However, it's important to note that "book up" as a phrase does not have a distinct etymology separate from the individual words "book" and "up".
