underlying (adj.)

• basal
• basic
• basilar
• bottom
• cardinal
• constituent
• constitutive
• covert
• critical
• crucial
• cryptic
• dormant
• elemental
• elementary
• esoteric
• essential
• fundamental
• hibernating
• hidden
• indispensable
• latent
• material
• muffled
• mystic
• necessary
• needful
• occult
• original
• possible
• potential
• primal
• primary
• primitive
• radical
• rudimentary
• sleeping
• submerged
• substantial
• substantive
• veiled
• virtual
• vital