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expression of boredom, by 1906. As an adjective, by 1956.
Unexciting; mediocre; dull: ho-hum sex and the dregs of countless six-packs/ After a ho-hum second quarter, stocks have perked up (1960s+)interjection
An expression of boredom (1924+)noun
Boring matter; dull tripe (1960s+)verb
To be bored with; be indifferent to: On the other hand, we shouldn't ho-hum the situation (1960s+)