1. A book consisting of sheets each of which is folded into twelve leaves; hence, indicating, more or less definitely, a size of a book
   - duodecimo

Derived forms: twelvemos

• fluoroform
• fluoroscope
• fluoroscopy
• fluorosis
• fluorouracil
• fluorspar
• fluosilicate
• fluosilicic acid
• fluoxetine
• fluoxetine hydrocholoride
• fluphenazine
• flurazepam
• flurazepam hydrochloride
• flurbiprofen
• flurry
• flush
• flush down
• flush it
• flush toilet
• flush-seamed
• flushed
• flushless toilet
• fluster
• flustered
• flute