Here are some possible words:
iambuses
iberians
icebergs
iceboats
icebound
iceboxes
icefalls
icehouse
ichorous
ichthyic
iconical
idahoans
idealism
idealist
ideality
idealize
idealogy
ideation
identify
identity
ideogram
ideology
idiocies
idiogram
idleness
idlesses
idolater
idolatry
idolised
idoliser
idolises
idolisms
idolized
idolizer
idolizes
idylists
idyllist
iffiness
ignified
ignifies
igniters
igniting
ignition
ignitors
ignominy
ignorant
ignorers
ignoring
ikebanas
illogics
illumine
illuming
illusion
illusive
illusory
imaginal
imagined
imaginer
imagines
imagisms
imagists
imamates
imbalmed
imbalmer
imbarked
imbecile
imbedded
imbibers
imbibing
imbruing
imitable
imitated
imitatee
imitates
imitator
immanent
immature
immenser
immersed
immerses
imminent
immixing
immobile
immodest
immolate
immortal
immotile
immunity
immunize
immuring
impacted
impacter
impactor
impaired
impairer
impalers
impaling
impanels
imparity
imparted
imparter
impasses
impearls
impeders
impeding
impelled
impeller
impellor
impended
imperial
imperils
imperium
impetigo
impinged
impinger
impinges
impishly
implants
implicit
imploded
implodes
implored
implorer
implores
implying
impolite
imported
importer
imposers
imposing
imposted
imposter
impostor
impotent
impounds
impowers
imprests
imprimis
imprints
imprison
improper
improved
improver
improves
impudent
impugned
impugner
impulsed
impulses
impunity
impurely
impurity
imputers
imputing
inaction
inactive
inasmuch
inboards
inbounds
inbreeds
incensed
incenses
inchoate
inchworm
incident
incising
incision
incisive
incisors
incisory
incitant
inciters
inciting
incitive
incitory
inclined
incliner
inclines
inclosed
incloser
incloses
included
includes
incoming
increase
incrusts
incubate
incumber
incurred
indebted
indecent
indented
indenter
indentor
indexers
indexing
indianan
indicate
indicium
indicted
indictee
indicter
indictor
indigene
indigens
indigent
indigoes
indirect
inditers
inditing
indolent
indorsed
indorsee
indorser
indorses
indorsor
inducers
inducing
inducted
inductee
inductor
indulged
indulger
indulges
indurate
industry
indwells
inedible
inedited
inequity
inerrant
inertial
inertias
inexpert
infamies
infamous
infantry
infarcts
infected
infecter
infector
infecund
inferior
infernal
infernos
inferred
inferrer
infested
infester
infidels
infields
infinite
infinity
infirmed
infirmly
inflamed
inflamer
inflames
inflated
inflater
inflates
inflator
inflects
inflexed
inflicts
inflight
influent
influxes
infolded
infolder
informal
informed
informer
infrared
infringe
infusers
infusing
infusion
infusive
ingather
ingenues
ingested
ingrains
ingrates
ingroups
inguinal
inhabits
inhalant
inhalers
inhaling
inherent
inhering
inherits
inhibits
inhumane
inimical
iniquity
initials
initiate
injected
injector
injurers
injuries
injuring
inkblots
inkhorns
inkiness
inklings
inkstand
inkwells
inlander
inlayers
inlaying
innately
innocent
innovate
innuendo
inputted
inquests
inquired
inquirer
inquires
inrushes
insanely
insanest
insanity
inscribe
insecure
inserted
inserter
insiders
insights
insignia
insisted
insister
insolent
insomnia
insomuch
inspects
inspired
inspirer
inspires
inspirit
installs
instance
instants
instated
instates
instills
instinct
instruct
insulars
insulate
insulins
insulted
insulter
insurant
insureds
insurers
insuring
intaglio
integers
integral
intended
intender
intenser
intently
interact
intercom
interest
interims
interior
intermit
intermix
internal
interned
internee
internes
interpol
interred
intersex
interval
intimacy
intimate
intoners
intoning
intrench
intrepid
intrigue
introits
intromit
intruded
intruder
intrudes
intrusts
intuited
inturned
intwined
intwines
intwists
inundant
inundate
invaders
invading
invalids
invasion
invasive
invected
inveighs
inveigle
invented
inventer
inventor
inverses
inverted
inverter
invertor
invested
investor
inviable
inviably
invitees
inviters
inviting
invocate
invoiced
invoices
invokers
invoking
involute
involved
involver
involves
inwardly
inweaved
inweaves
iodizers
iodizing
iodoform
ionicity
ionising
ionizers
ionizing
iranians
irefully
iridiums
irishman
irishmen
ironbark
ironclad
ironical
ironings
ironists
ironside
ironware
ironweed
ironwood
ironwork
Iroquois
irrigate
irritant
irritate
irrupted
iscariot
islanded
islander
isobaric
isocline
isolable
isolated
isolates
isolator
isomeric
isometry
isomorph
isoprene
isostasy
isotherm
isotonic
isotopes
isotopic
israelis
issuable
issuably
issuance
istanbul
isthmian
Italians
itchiest
itchings
itemized
itemizer
itemizes
iterated
iterates
graffiti = writings or drawings on walls and other flat surfaces
Eight letter words with the fourth letter T are:vestmentseatmateabstracttortoisemantillasouthernnorthernamethystplatinumwisteriabuttresssubtlety
answeredbagwormschowdersdogwoodsearwaxesflywheelgrownupsinkwellskeywordsmidwivesnetworkspinwheelredwoodssnowshoeviewings
revolver
takeouts
reversed
Withhold, withheld, fishhook
ballroomballgamebafflingbattlingbillablebillfoldbloomingbutteredcommutercommentscommandocollapsecollagencarriagecurrencycommonlydifferedhammeredfreebornfreebasefreehandfreeloadhorriblygreenerygroomingfloodlithappenedjudderedmarriagepepperedsleepingsnoopingscoopingspeedingsufferedsuddenlysuggestssuppliedsupportssupposedsuppresssurroundsweepingtrammels
dividing
reversed
benefitsfanaticalfinishedgeneralsgenerategeneroushonoraryminicampmonogamymonogrammonoxidemonorailrenegaderenewalssinistertenementvenerate
redeemed
bladders