1. A book to which you can refer for authoritative facts
   - reference book, reference, reference work

Derived forms: books of facts

Type of: book

• order Uredinales
• order Urodella
• order Uropygi
• order Urticales
• order Ustilaginales
• order Volvocales
• order Xiphosura
• order Xyridales
• order Zeomorphi
• order Zygnemales
• order Zygnematales
• order-Chenopodiales
• ordered
• ordered series
• orderer
• ordering
• orderliness
• orderly
• orderly sergeant
• ordinal
• ordinal number
• ordinance
• ordinand
• ordinarily
• ordinariness