Verb

• S: (v) rarefy, attenuate (weaken the consistency of (a chemical substance))
• S: (v) attenuate (become weaker, in strength, value, or magnitude)

Adjective

• S: (adj) attenuated (of an electrical signal; reduced in amplitude with little or no distortion)
• S: (adj) attenuate, attenuated, faded, weakened (reduced in strength) "the faded tones of an old recording"
• similar to
• antonym