COMMENT: Reconstructed for the PEC level. The verbal stem itself is preserved only in a few languages (Nakh, Tind., Bezht., Darg.). Very well represented, however, are two common EC derivates: *r-ĕŁō 'threshing, grain ready for threshing' and *m-ɨ̄(r)ŁV 'threshing board'. PA *bilimV (corresponding to the latter form) is probably a metathesis < *mili-bV (with *-bV as a former plural affix). If our analysis is right, we have here another case of the PEC instrumental prefix *m-.