compunction n.

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.

also *peug-, Proto-Indo-European root meaning "to prick."

It forms all or part of: appoint; appointment; bung; compunction; contrapuntal; expugn; expunge; impugn; interpunction; oppugn; pink; poignant; point; pointe; pointillism; poniard; pounce; pugilism; pugilist; pugnacious; pugnacity; punch (n.1) "pointed tool for making holes or embossing;" punch (n.3) "a quick blow with the fist;" punch (v.) "to hit with the fist;" puncheon (n.2) "pointed tool for punching or piercing;" punctilio; punctilious; punctual; punctuate; punctuation; puncture; pungent; punty; Pygmy; repugn; repugnance; repugnant.

It is the hypothetical source of/evidence for its existence is provided by: Greek pyx "with clenched fist," pygme "fist, boxing," pyktes "boxer;" Latin pugnare "to fight," especially with the fists, pungere "to pierce, prick."

"causing compunction, pricking the conscience," c. 1600, from stem of compunction + -ous. Related: Compunctiously; compunctiousness.