by-thing|ˈbaɪθɪŋ|[f.by- 4, 5 + thing.]That which is not the main thing; a matter by the way, or for by-times.1721StrypeEccl.Mem.I. i. xxiv. 174Not[content to swear]to the whole act, some by-things in it not agreeing to their judgments.1859G. WilsonE. Forbes x. (1861) 318Only..as a kind of by-thing could he find time for zoological..pursuits.1884TennysonBecket iii. iii. 132These are by-things In the great cause.