WordNet sense 1 (good physical condition; being in shape or in condition):

fitness, good condition, good shape, physical fitness

WordNet sense 2 (the magnitude of sound (usually in a specified direction)):

loudness

WordNet sense 3 (the quality of being sharp and clear):

distinctness, sharpness

WordNet sense 4 (the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale):

hardness