- safe
- safety barrier
- safety bolt
- safety brigade
- safety clearance
- safety cutoff
- safety hook
- safety rail
- safety record
- safety rim
- sag
- sag tie
- sagger
- round groove
- round slot
- round trunk
- roundabout island
- rounded corners
- roustabout
- route location
- route map
- router plane
- routine maintenance
- routine slip
- row height
- row matrix
- row vector
- royal tombs
- rub
- rub out
- rubber
- rubber bearing
- rubber finish
- rubber gloves
- rubber mallet
- rubber sheath
- rubber-tyre
- rubbing
- rubbish disposal
- rubbish-lorry
- rubble
- rubble arch
- rubble bed
- rubble drain
- rubble wall
- ruberoid grade
- rug
- ruin
- ruinated monument
- ruins
- ruler
- ruling gradient
- rung ladder
- runner
- running bond
- running head
- running maintenance
- running repair
- running speed
- runway
- rupture strength
- rural highway
- rush
- rush mat
- rush pressboard
- rust removal
- rust-prevention
- rustic
- rustic masonry
- rustic stucco
- rustle finish
- rustless iron
- sabin
- sacristy
- rudder
- ruined monument
- rule
- ruling pen
- run
- rung
- running ground
- running roller
- running soil
- runoff triangle
- runway length
- rupture condition
- rupture modulus
- rural road
- rural settlement
- rust-eaten
- rust-proof
- rustic dressing
- rusticated ashlar
- rut
- sacchometer
- sacked cement
- sacrarium
- saddleback
- safe deposit
- safe pressure