Severity - Vine's Expository Dictionary of New Testament Words
Severity[ 1,,G663, apotomia ]
steepness, sharpness" (apo, "off," temno, "to cut;" tome, "a cutting"), is used metaphorically in Romans 11:22 (twice) of "the severity of God," which lies in His temporary retributive dealings with Israel. In the papyri it is used of exacting to the full the provisions of a statue. Cp. the adverb apotomos, "sharply" (which see).
[ 2,,G857, apheidia ]
primarily "extravagance" (a, negative, pheidomai, "to spare"), hence, "unsparing treatment, severity," is used in Colossians 2:23, RV, "severity (to the body)," AV, "neglecting of" (marg., "punishing, not sparing"); here it refers to ascetic discipline; it was often used among the Greeks of courageous exposure to hardship and danger.