noun, feminine/ˈreɡla/plural: reglas
rule (regulation, norm); ruler (measuring stick); menstruation, period
“Tiene la regla.” — She's on her period.
Etymology tree Proto-Indo-European *h₃reǵ- Proto-Indo-European *-eti Proto-Indo-European *h₃réǵeti Proto-Italic *regō Latin regō Proto-Indo-European *-tḗr Proto-Indo-European *-trom Proto-Indo-European *-tlom, *-dʰlom Latin -ula Latin regulaslbor. Spanish regla Semi-learned borrowing from Latin regula. Compare Portuguese regra. Doublet of reja, which is inherited. Cognate with English rule.