orthostasis

English

Etymology tree

Proto-Indo-European *h₃erdʰ-der.

Proto-Hellenic *ortʰwós

Ancient Greek ὀρθός (orthós)lbor.

English ortho-

English stasis

English orthostasis

From ortho- + stasis.

orthostasis (uncountable)

(sciences) The act or status of standing upright.
Synonym: orthostatism (uncommon)

lightheadedness during orthostasis
(sciences, especially medicine, informal) Ellipsis of orthostatic hypotension.
A history of orthostasis prompts some caution in prescribing of antihypertensives.