- circuit misclosure
- circular beam
- circular cantilever
- circular cofferdam
- circular dragline
- circular motorway
- circular path
- circular shed
- circular street
- circular tunnel
- circulation pipework
- circulation road
- circumferential rib
- circumscribe
- circus
- cistern tap
- citadel
- cite formally
- city
- city boundary
- city gate
- city plan
- city wall
- civic architecture
- civic building
- civic centre
- civic square
- civil building
- civilization
- clad
- cladding boards
- cladding glass
- cladding panel
- cladding structures
- claim
- clamped pinned
- clamping device
- clapboard
- clarification basin
- clarification equipment
- clarification structure
- clarification time
- clarifier
- clasp knife
- class
- classical period
- classical tradition
- classicism
- classics
- classification characteristics
- classification count
- classification test
- classification yard
- classifier
- clathrate
- claw bar
- clawplate
- clay brick
- clay content
- clay cutter
- clay dust
- clay mineral
- clay paddle
- clay powder
- clay preparation
- clay product
- clay sample
- clay slate
- clay slope
- clay stone
- clay wall
- clayed soil
- clayey dolomite
- clayey sand
- clayish fraction
- clean
- clean situation
- cleaner
- clear
- clear film
- clear span
- clear zone
- chlorination
- chlorination plant
- chlorization
- choir screen
- choke dike
- choker
- choking coil
- chopped strands
- chord
- chord splice
- chord stress
- chore
- chorograph
- chorography
- christmas
- chrome bricks
- chrome green
- chrome iron