poise; assurance; facility; confidence and ease in performance
At the party, he recited several poems with great aplomb.
Take it as a-bomb, so a bomb defusing team must have following characteristics: assurance, balance, confidence, coolness, equanimity, nerve, nonchalance, poise, surety, tact. And these are the synonyms of aplomb!!! aplomb = a + pl (people) + OM; people normally chant 'OM' when they do meditation to keep themselves cool under strain.