- intrastate traffic
- introduced plants
- intumescent paint
- inundation irrigation
- invading sea
- invention proposal
- inverse
- inversion
- invert
- invert ratio
- inverted arch
- inverted deflection
- inverted roof
- inverted roofing
- inverted siphon
- investment fund
- investor
- invisible outline
- involution
- inwash
- ion exchange
- ionic
- ionic order
- ionogenic process
- Irish architecture
- irish bridge
- iron cement
- iron filing
- iron gate
- iron girder
- iron hut
- iron scaffold
- iron tie
- iron wood
- iron-bar
- ironmongery
- ironware
- ironwood
- irradiation
- irrational number
- irregular pitch
- irregular plan
- irreplaceable
- irrigation
- irrigation ditch
- irrigation gallery
- irrigation network
- irrigation pool
- irruptive
- ion trap
- ionite filter
- ionite flushing
- ionogenic absorbent
- iron
- iron aggregates
- iron bolt
- iron bridge
- iron clay
- iron foundry
- iron sand
- iron sheet
- iron worker
- iron-mould
- ironwork fault
- irregular figure
- irregularity
- irreversible
- irrigated area
- irrigation canal
- irrigation facilities
- irrigation module
- irrigation system
- irrigation tunnel
- irrotational flow
- islamic architecture
- island
- island bath
- island breakwater
- island embankment
- island sink
- island station
- isle
- iso curve
- isobase
- isobaths
- isoclinal
- isocline
- isodynamic line
- isogal
- isogam
- isogeothermal line
- isogon
- isogonic line
- isogonie chuit
- isograd
- isohaline
- isohyetal
- isohypse
- isolate footing
- isolated