transitive verb attenuated -·at′ed, attenuating -·at′·ing

1. to make slender or thin
2. to dilute or rarefy
3. to lessen in severity, value, amount, intensity, etc.; weaken
4. Electronics to reduce the amplitude or strength of (an electrical signal)
5. Microbiol. to reduce the virulence of (a bacterium or virus) usually to make a vaccine

Etymology: < L attenuatus, pp. of attenuare, to make thin < ad- to + tenuare < tenuis, thin

intransitive verb

adjective

1. attenuated
2. Bot. tapering gradually to a point, as the base of a leaf