attenuate (v.) Look up attenuate at Dictionary.com
"to make thin, to make less," 1520s, from Latin attenuatus, past participle of attenuare "to make thin, lessen, diminish," from assimilated form of ad "to" (see ad-) + tenuare "make thin," from tenuis "thin," from PIE root *ten- "to stretch." Related: Attenuated; attenuating. Earlier was Middle English attenuen "to make thin (in consistency)," early 15c.