basal (adj.)

• aboriginal
• basic
• basilar
• beginning
• bottom
• bottommost
• central
• constituent
• constitutive
• crucial
• elemental
• elementary
• embryonic
• essential
• fundamental
• generative
• genetic
• germinal
• lowermost
• lowest
• material
• nethermost
• original
• pregnant
• primal
• primary
• primeval
• primitive
• primordial
• pristine
• radical
• rudimentary
• seminal
• substantial
• substantive
• underlying