Informal Boring and dull; routine: "a ho-hum speaker who couldn't capture the attention of the conventioneers” ( Chicago Tribune).
You can use ho hum when you want to show that you think something is not interesting, remarkable, or surprising in any way.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
You can say ho hum to show that you accept an unpleasant situation because it is not very serious.
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