"action of blocking or stopping up," especially, in medicine, "constipation," 1590s, from Latin obstipationem (nominative obstipatio), noun of action from past-participle stem of *obstipare "action of blocking or stopping up," from ob "in front of; in the way of" (see ob-) + stipare "to press together, to pack" (see stiff (adj.)).
obstetrician
obstetrics
obstinacy
obstinance
obstinate
obstipation
obstreperous
obstruct
obstruction
obstructionism
obstructionist