The only free and comprehensive online etymological dictionary of the Spanish language
medir (Verb) "to measure"
12th cent. From Latin metiri 'id.' From Proto-Italic *mēti- 'id.' From Proto-Indo-European *meh1-ti̯- 'id.' From the root *meh1- 'id.'
Indo-European
Romance
Portuguese medir, Sardinian medire
Celtic
Old Irish midithir "to measure," Middle Welsh meðu "to think," meddu "rule," Middle Cornish medhes "to say"
Germanic
Gothic mitan "to measure," Old Norse meta "to evaluate," Old High German mezzan "to measure," Old English metan 'id.' (English to measure)
Hellenic
Ancient Greek μέδομαι (médomai) "to care for"
Armenian
Armenian mit-kʿ "mind"
Indo-Iranian
Young Avestan vī-māδaiiaṇta "they must measure"

"In historical times the root *med- designated a great variety of different things: “govern,” “think,” “care for,” “measure.” ... It can be defined as “measure”—not “measurement,” but “moderation” (Lat. modus, modestus)." ~ E. Benveniste, Indo-European Language and Society (1973)