CONCISION, Gr. κατατομή, G2961, a hapax legomenon (Phil 3:2). The term means “mutilations,” “cutting apart in pieces.” It is used with “circumcision” in a play on words, the RSV rightly renders “mutilate.” Paul uses a similar reference to the full-scale cutting, castration of the circumcisers (Gal 5:12). A similar play on the term is noted in Diogenes Laertius (a.d. 200-250) 6:24.

International Standard Bible Encyclopedia (1915)

A term by which Paul contemptuously designates the merely fleshly circumcision upon which the Judaizers insisted as being necessary for Gentileconverts (Php 3:2), as distinguished from peritome, the true circumcision (Php 3:3). Compare Ga 5:12 and De 23:1, and see Circumcision.