anodont dentition - argyrodite
- aple-shaft hoist
- aplite
- aplitic
- aplitic texture
- aplodiorite
- aplogranite
- aplome
- aplowite
- apoanalcite
- apobsidian
- apoda
- apodal
- apodemes
- apogean range
- apogranite
- apogrite
- apomagmatic
- apophyllite
- apophysal injection
- apophyse
- apophysis
- aporhyolite
- aporosa
- aposandstone
- apospory
- apotype
- Appalachia
- Appalachian trough
- apparent
- apparent (interval) density
- apparent attenuation
- apparent cohesion
- apparent color
- apparent conductivity curve
- apparent dip
- apparent downthrow
- apparent fault displacement
- apparent frequency
- apparent heave
- apparent heave slip