一叢[hitomura] copse
稲叢[inamura] stack of rice straw
叢がる[muragaru] to swarm
叢雨[murasame] passing shower
叢時雨[murashigure] autumn shower

叢書[sousho] series (of publications)
叢生[sousei] dense growth
叢談[soudan] collection of stories
叢氷[souhyou] pack ice
叢立ち[soudachi] standing in a group

論う[agetsurau] to discuss
ファジィ理論[fajiiriron] fuzzy theory
意味論[imiron] semantics
異論[iron] different opinion
一元論[ichigenron] monism

一神論[isshinron] monotheism
一般論[ippanron] prevailing view
運命論[unmeiron] fatalism
概論[gairon] introduction
各論[kakuron] item-by-item discussion