Merriam-Webster Collegiate Dictionary - poise

 I. verb  (~d; poising)  Etymology: Middle English, to weigh, ponder, from Anglo-French peiser, ~r, from Latin pensare — more at pensive  Date: 1598  transitive verb  1.  a. balance; especially to hold or carry in equilibrium carried a water jar ~d on her head  b. to hold supported or suspended without motion in a steady position ~d her fork and gave her guest a knowing look — Louis Bromfield  2. to hold or carry (the head) in a particular way  3. to put into readiness ; brace  intransitive verb  1. to become drawn up into readiness  2. hover  II. noun  Etymology: Middle English poyse weight, heaviness, from Anglo-French peis, pois, from Latin pensum, from neuter of pensus, past participle of pendere to weigh — more at pendant  Date: 1649  1. a stably balanced state ; equilibrium a ~ between widely divergent impulses — F. R. Leavis  2.  a. easy self-possessed assurance of manner ; gracious tact in coping or handling; also the pleasantly tranquil interaction between persons of ~ no angry outbursts marred the ~ of the meeting  b. a particular way of carrying oneself ; bearing, carriage  Synonyms: see tact  III. noun  Etymology: French, from Jean Louis Marie Poiseuille died 1869 French physician and anatomist  Date: 1913 a centimeter-gram-second unit of viscosity equal to the viscosity of a fluid that would require a shearing force of one dyne to impart to a one-square-centimeter area of an arbitrary layer of the fluid a velocity of one centimeter per second relative to another layer separated from the first by a distance of one centimeter