- acid level
- acid salt
- acid sludge
- acid test
- acid treating
- acid treatment
- acid water
- acidic water
- acidifying agent
- acidity level
- acerbity
- acescency
- acetaldol
- acetifier
- acetone
- acetonitrile
- acetophenone
- acetyl
- acetyl value
- acetylene
- acetylene lighting
- acetylide
- acetylsalicylic
- Acheson graphite
- achromatic
- aci-from
- acid Acid
- acid bath
- acid bottle
- acid content
- acid cure
- acid elevator
- acid etching
- acid function
- acid heat
- acid lava
- acid nature
- acid oil
- acid phosphate
- acid pump
- acid recovery
- acid refining
- acid refractory
- acid tank
- acid tar
- acid wash
- acidifier
- acidulous
- acoustic basement
- acoustic log
- acoustic measurement
- acoustical sealant
- acre
- acrylic acid
- acrylic fiber
- acrylic rubber
- acrylonitrile rubber
- actinide element
- actinoid
- actinology
- activated
- activated alumina
- activated carbon
- activated clay
- activated complex
- activated state
- activation
- activation area
- activation entropy
- activation log
- activation parameter
- active agent
- active carbon
- active complex
- active crater
- active deposit
- active ferment
- active hydrogen
- active nitrogen
- active solvent
- activity coefficient
- actor
- acyclic complex
- acyclic compound
- acyl
- acidulate
- acidulous water
- acierate
- acoustic absorbent
- acoustic method
- acreage rent
- acrolein resin
- acrylate
- acrylic paint
- action
- actual gradient
- actual income
- actual order
- actual porosity
- actual value