[in.fin.i.tes.i.mal] n [NL infinitesimus infinite in rank, fr. L infinitus] (1706): an infinitesimal quantity or variable
[2]infinitesimal adj (1710) 1: taking on values arbitrarily close to but greater than zero
2: immeasurably or incalculably small -- in.fin.i.tes.i.mal.ly adv