i·so·pi·es·tic 
(ī′sō-pī-ĕstĭk, -pē-)
(ī′sō-pī-ĕstĭk, -pē-)adj.
Marked by or indicating equal pressure; isobaric.
n.
See isobar.
[ISO- + Greek piestos, able to be compressed (from piezein, to press tight; see sed- in the Appendix of Indo-European roots) + -IC.]