in·fra·class 
(ĭnfrə-klăs′)
(ĭnfrə-klăs′)n.
A taxonomic category of related organisms ranking below a subclass and above an order or superorder.
- fluoridate
- fluoridation
- fluoride
- fluorination
- fluorine
- fluorite
- fluoro-
- fluorocarbon
- fluorochemical
- fluorochrome
- fluorography
- fluorometer
- fluorometry
- fluoroquinolone
- fluoroscope
- fluoroscopic
- fluoroscopically
- fluoroscopist
- fluoroscopy
- fluorosis
- fluorotic
- fluorouracil
- fluorspar
- fluoxetine
- fluphenazine