Origin of perpendMiddle English perpoynt from Middle French parpain from Vulgar Latin an unverified form perpannium
Origin of perpendClassical Latin perpendere: see perpendicular
verbper·pend·ed, per·pend·ing, per·pends Archaic
Origin of perpendLatin perpendere per- per- pendere to weigh ; see (s)pen- in Indo-European roots.
(third-person singular simple present perpends, present participle perpending, simple past and past participle perpended)
From Latin perpendere, from per- + pendere (“to weigh").