automatic locking - barren zone
- avalanche defences
- avalanche ice
- avalanche of ions
- avalanching
- avelinoite
- avelionite
- aven
- aventurescence
- aventurine
- aventurine feldspar
- aventurine quartz
- aventurism
- avenue
- average
- average 2m thick
- average amplitude
- average annual precipitation
- average annual temperature
- average diurnal temperature
- average gas-saturated thickness
- average gold grade
- average gold grade in mineable gold reserve
- average grade
- average grading
- average hade
- average igneous rock
- average net HC
- average number of common shares
- average of test results
- average oil and gas saturated net pay thickness
- average output
- average productivity per unit volume
- average rate
- average sample
- average trend
- average trip length
- average velocity function
- average yearly gross discovery
- average-size coal
- averaging