本の[honno] mere
異本[ihon] different edition
一坪本社[hitotsubohonsha] small company headquarters located in Tokyo simply for name value
一本[ippon] one long cylindrical thing
一本気[ippongi] single-minded (esp. personality or person)

一本橋[ipponbashi] (a) log bridge
一本建て[ippondate] (a) single standard
一本松[ipponmatsu] solitary pine tree
一本杉[ipponsugi] (a) solitary cryptomeria tree
一本槍[ipponyari] guiding principle

アルファ線[arufasen] alpha rays
エックス線[ekkususen] X-ray
サイン曲線[sainkyokusen] sinusoid
スピード線[supiidosen] speed lines
緯線[isen] parallel

一次線輪[ichijisenrin] primary coil
一線[issen] line
一直線[icchokusen] straight line
一番線[ichibansen] track no. 1
一塁線[ichiruisen] first-base line