um

Etymology 1

Onomatopoeic.

intj

1. Expression of hesitation, uncertainty or space filler in conversation.
   Um, I don’t know.
   Let’s see... um... how about this?
   It's a great test of the claims of open-source gurus, who say that a self-motivated community can outcode any team working for a single employer—like, um, Microsoft. 2002, Newsweek, volume 140, page lxxx
2. (chiefly US) Dated spelling of mmm.
   "About the same, wherever you go," he agreed. "Um," I said. 1963, Kurt Vonnegut, Cat's Cradle, Dell Publishing Co., Inc., page 65
3. (UK, childish) An expression of shocked disapproval used by a child who witnesses forbidden behavior.
   While I was in her room, Sam walked by and said, “Um, I'm telling!” “You're telling what?” I asked. “You're reading Tori's journal,” she said. 2011, Kimberly Willis Holt, Piper Reed, Clubhouse Queen
   Mair used to look after Laura. If anyone threatened to tease her, Mair would stand up straight, point her finger at the enemy and shout, 'Um! I'm telling on you!' 2021, Sarah Strangeways, The Gingerbread House, page 13

verb

1. (intransitive) To make the um sound to express uncertainty or hesitancy.
   Meanwhile, in the popular mind umming was simply a bad habit, akin to spitting or picking one’s nose. 2007, Michael Erard, Um... Slips, Stumbles, and Verbal Blunders, and What They Mean, page 136

Etymology 2

From Middle English um, from Old Norse um, umb (“around, about”), from Proto-Germanic *umbi (“around”), from Proto-Indo-European *h₂m̥bʰi (“round about, around”). Cognate with Old English ymbe (“around”), West Frisian om (“around”), Dutch om (“around”), German um (“around”). More at umbe.

prep

1. Alternative form of umbe