群々

Reduplication of 群 (mura, “group, grouping, throng, crowd, swarm”).[1][2]

First attested in the early 900s.[1]

• (Tokyo) む​らむら [múꜜràmùrà] (Atamadaka – [1])[2][3]
• IPA^(key): [mɯ̟ᵝɾa̠mɯ̟ᵝɾa̠]

群(むら)々(むら) or 群々(ムラムラ) • (muramura) 

1. [from early 900s] in a mottled or splotchy fashion, irregularly
2. [from 1490s] in an energetic and swarming or flocking manner
3. [from 1670s] puffingly, billowingly, as clouds or smoke may move in a way similar to a flock of birds or swarm of insects
4. [from 1850s] suddenly and irresistibly, as of an emotion welling up
5. [from 1880s] enragedly, flying off the handle

群(むら)々(むら)する or 群々(ムラムラ)する • (muramura suru) suru (stem 群(むら)々(むら)し (muramura shi), past 群(むら)々(むら)した (muramura shita))

1. (colloquial) to be sexually turned on, to be horny