a must

That which is requisite, necessary, or indispensable. I know this book is a difficult read, but it's an absolute must if you enjoy literature. Taking the introductory course is a must if you want to sign up for the advanced class.

a must

A necessity; a requirement. For example, The Louvre is a must for visitors to Paris, or This book is a must for serious students of English. [Late 1800s]

a must

verb

See a must do

Common Names:

Name	Pronounced	Usage
Cecilia	sə-SEE-lee-ə (English), sə-SEEL-yə (English), che-CHEE-lyah (Italian), the-THEE-lyah (Spanish), se-SEE-lyah (Latin American Spanish), se-SEEL-yah (Danish, Norwegian), SE-see-lee-ah (Finnish)	English, Italian, Spanish, Swedish, Danish, Norwegian, Finnish, Dutch, German
Allen	AL-ən (English)	English, Scottish
Sterling	['stə:liŋ]
Klasina	klah-SEE-nah	Dutch
Ogden	['ɔ:gdən]
Shailaja	-	Hinduism, Indian, Telugu