Merriam-Webster's Collegiate Dictionary:
informant
informatics
information
information highway
information retrieval
information science
information superhighway
information theory
informational
informationally
informative
informatively
informativeness
informatorily
informatory
informed
informed consent
informedly
informer
infotainment
infra
infra dig
infra-
infract
infraction
infrahuman
infrangibility
infrangible
infrangibly
infraorder
infrared
infrasonic
infraspecific
infrastructural
infrastructure
infrequence
infrequency
infrequent
infrequently
infringe
infringement
infringer
infundibular
infundibulum
infuriate
infuriatingly
infuriation
infuse
infuser
infusibility
infusible
infusibleness
infusion
infusorial earth
infusorian
ing?nue
ingather
ingathering
inge
ingenious
ingeniously
ingeniousness
ingenue
ingenuity
ingenuous
ingenuously
ingenuousness
ingersoll
ingest
ingesta
ingestible
ingestion
ingestive
ingle
inglenook
inglewood
inglorious
ingloriously
ingloriousness
ingolstadt
ingot
ingot iron
ingrain
ingrained
ingrainedly
ingrate
ingratiate
ingratiating
ingratiatingly
ingratiation
ingratiatory
ingratitude
ingredient
ingres
ingress
ingression
ingressive
