(anatomy) The groove between the buttocks that runs from just below the sacrum to the perineum.

Third-person singular simple present indicative form of pixellate

(uncountable) The quality of being irreligious. / (countable) An impious action or utterance.

(medicine, pathology) Abbreviation of airborne infection isolation. / (biochemistry) Abbreviation of angiotensin II. / (linguistics) Abbreviation of atavistic-idiosyncratic idiolect.