"functional" - key terms from Wikipedia

density functional
density functional	theory
energy functional
fully functional
functional
functional	analysis
functional	art
functional	buttons
functional	calculus
functional	dependency
functional	derivative
functional	development phase
functional	dyspepsia
functional	earth
functional	equation
functional	form
functional	genomics
functional	grammar
functional	group
functional	groups
functional	illiteracy
functional	impairments
functional	integral
functional	kinds
functional	languages
functional	layer
functional	layout
functional	leadership
functional	magnetic resonance imaging
functional	measure
functional	model iteration
functional	neuroimaging
functional	pitch recognition
functional	products
functional	profile
functional	programming
functional	programming languages
functional	prototype
functional	psychology
functional	requirements
functional	role
functional	specification
functional	style
functional	units
functional	unity
kinetic energy functional
limited functional	support
pure functional
purely functional
redundant functional	units