うん

Compare Korean 응 (eung, “yeah, yes”).

• (Tokyo) うん [úꜜǹ] (Atamadaka – [1])^[1]
• IPA^(key): [ɯ̟̃ɴ]

• IPA^(key): /m̩/, [m̩˦˨]
  • Usually pronounced with the mouth closed.

うん • (un) 

1. (informal) yeah, uh-huh, mhm (an interjection expressing agreement)

• はい (hai, “yes”)

• ううん (ūn): nope, nah, nuh-uh

Onomatopoeia of the grunting noise made when straining oneself in effort.^[2]

The prefix usage appears in the Kanto region during the Edo period.^[2]

• IPA^(key): [ɯ̟̃ɴ]

うん • (un) 

1. strainingly, with a grunt
2. sufferingly, groaningly

Takes the adverbial particle と (to)

うん • (un-) 

1. (archaic) added to various verbs to indicate forceful or excessive action

   うん飲(の)む

   unnomu

   to drink with gusto

• うんこ (unko, “poop”)
• うんち (unchi, “poop”)

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

うん • (un-) 

1. several; some vague number of

   Synonym: 数 (sū)

   うん十億円 ― several billions of yen

   うん十年 ― several tens of years

   うん千万 ― several thousand myriad

   うん億 ― several hundreds of millions