1. imperturbable self-possession, poise, or assurance
2. the perpendicular, or vertical, position
"The bride walked down the aisle with aplomb until she tripped and fell."
"Bob accidentally walked into the women's bathroom but he handled the situation with such aplomb that he did not get arrested."
Origin: (from etymonline.com)
"'assurance, confidence,' 1828, from French aplomb (16c.), literally 'perpendicularity,' from phrase à plomb 'poised upright, balanced,' literally 'on the plumb line,' from Latin plumbum '(the metal) lead' (see plumb (n.)), of which the weight at the end of the line was made."
Awkwardness rating: 3
|She walked down the aisle with aplomb. (afloral.com)|