hollow

arched cleft cupped curved depressed dimpled excavated indented notched pitted striated sunken vaulted void

alveolate carved out cavernous concave cup-shaped deep-set incurved infundibular not solid troughlike unfilled vacant

convex earnest frank full genuine high honest light meaningful raised real sincere soft solid substantial truthful

muted

dull echoing flat low muffled mute resounding ringing roaring rumbling sounding vibrating

cavernous clangorous ghostly reverberant sepulchral thunderous toneless vibrant

clear elevated sharp

convex earnest frank full genuine high honest light meaningful raised real sincere soft solid substantial truthful

empty fruitless futile pointless useless worthless

idle

nugatory otiose specious unavailing vain

copious fruitful productive profitable useful valuable worthwhile

convex earnest frank full genuine high honest light meaningful raised real sincere soft solid substantial truthful

flimsy

cynical deceitful faithless hypocritical insincere treacherous unsound weak

convex earnest frank full genuine high honest light meaningful raised real sincere soft solid substantial truthful

cavern

basin bottom bowl cave cavity chamber channel cleft concavity crater cup dale den depression dimple dip dish excavation groove gulf hole indentation notch pit pocket sag scoop sinkhole socket trough vacuity valley void

sinkage

closure increase mountain rise solid

channel chase corrugate dent dig dish ditch excavate furrow gorge groove indent notch pit rabbet remove rut scoop shovel trench

fill flush

make convex raise