google
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1960s: blend of benzodiazepine and amide.
wiktionary
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From (benzo)diazep(ine) + am(ide).
etymonline
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diazepam (n.)
"Valium," 1961, from (benzo)diazep(ine) + -am, apparently an arbitrary suffix. The element diazo- denotes two nitrogen atoms combined with one hydrocarbon radical.
