automatic locking - barren zone
- back-leg
- back-leg bracing
- back-river
- back-shift
- back-slope
- back-stope
- back-water
- back-weight
- backbeach
- backbone
- backdeep
- backdeeps
- backdraught
- backend
- backfall
- backfill
- backfill material
- backfill thickener
- backfilled trench
- backfilling
- backfilling material
- backfilling of gouge
- backfilling strinkage
- backflooding
- backflow
- backfolding
- background
- background density
- background ionization
- background level of metal
- background medium
- background noise
- background value
- background variations
- background velocity
- background-corrected
- backhead
- backhoe
- backhoe excavator
- backing