Proto-Indo-European root meaning "one; as one, together with."
It forms all or part of: anomalous; anomaly; assemble; assimilate; ensemble; facsimile; fulsome; hamadryad; haplo-; haploid; hendeca-; hendiadys; henotheism; hetero-; heterodox; heterosexual; homeo-; homeopathy; homeostasis; homily; homo- (1) "same, the same, equal, like;" homogenous; homoiousian; homologous; homonym; homophone; homosexual; hyphen; resemble; same; samizdat; samovar; samsara; sangha; Sanskrit; seem; seemly; semper-; sempiternal; similar; simple; simplex; simplicity; simulacrum; simulate; simulation; simultaneous; single; singlet; singular; some; -some (1); -some (2); verisimilitude.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sam "together," samah "even, level, similar, identical;" Avestan hama "similar, the same;" Greek hama "together with, at the same time," homos "one and the same," homios "like, resembling," homalos "even;" Latin similis "like;" Old Irish samail "likeness;" Old Church Slavonic samu "himself."
see jail (n.), you tea-sodden football hooligan. Formerly in official use in Britain, and thus sometimes regarded in U.S. as a characteristic British spelling (though George Washington used it); by the time of OED 2nd edition (1980s) both spellings were considered correct there; the g- spelling is said to have been dominant longest in Australia.
[T]he very anomalous pronunciation of g soft before other vowels than e, i, & y ... is a strong argument for writing jail [Fowler]