Main Entry: 1re·cal·ci·trant Pronunciation Guide
Etymology: Late Latin recalcitrant-, recalcitrans, from present participle of recalcitrare to be stubbornly disobedient, from Latin, to kick back, from re- + calcitrare to kick, from calc-, calx heel -- more at CALK
1 : obstinately defiant of authority or restraint : stubbornly disobedient <recalcitrant and dangerous heretics and obstructionists -- G.L.Kline> <a recalcitrant child> <call forth the forces of the Union to coerce recalcitrant states -- S.E.Morison & H.S.Commager>
2 a : difficult or impossible to handle or operate : UNMANAGEABLE <the materials in these fields are more complex and more recalcitrant than the simpler and more readily measurable phenomena of the languages -- Mortimer Graves> <the car had a recalcitrant gearshift lever -- M.M.Musselman> b : not responsive to treatment <many of these patients were suffering from recalcitrant forms of the disease -- Journal American Medical Association> c : RESISTANT -- usually used with to <this subject is recalcitrant both to observation and to experiment -- G.G.Simpson> <nothing perhaps is more recalcitrant to logical systematization than local custom -- G.H.Sabine>
synonym see UNRULY
I found this interesting discussion of the word "recalcitrant" and an apparently new word "incalcitrant".
Main Entry: cal·ci·um Pronunciation Guide
Inflected Form(s): -s
Usage: often attributive
Etymology: New Latin, from Latin calc-, calx lime + New Latin -ium -- more at CHALK
1 : a silver-white rather soft bivalent metallic element of the alkaline-earth group that quickly tarnishes in air and when heated burns with a brilliant light, used chiefly in alloys and in various metallurgical processes, often as a scavenger, and never occurring native but very common in combination in certain minerals and rocks, especially as a carbonate (as in limestone), sulfate, or phosphate, in practically all natural waters, and in most animals and plants as an essential constituent -- symbol Ca; see ELEMENT table
2 a : a very strong white light source given by lime heated to incandescence in an oxyhydrogen flame -- compare LIMELIGHT b : the flame of acetylene gas generated by reaction of calcium carbide with water
In the etymology for the word "recalcitrant", MW unabridged indicates the latin root "calc" or "calx" means "heel".
In the etymology for the word "calcium" the same root appears but in this case MW indicates it means "lime".