The only free and comprehensive online etymological dictionary of the Spanish language
cerrar (Verb) "to close"
12th cent. From Vulgar Latin serrare 'id.' From Latin serere "to lock," but originally "to join." From Proto-Italic *ser-e/o- 'id.' From Proto-Indo-European *ser-e/o- "to join together."
Indo-European
Romance
Asturian zarrar, Portuguese cerrar, Galician cerrar, French serrer, Italian serrare
Italic
Oscan aserum "to lay"
Germanic
Gothic sarwa "armor," Old Norse sørvi "collar," Old High German saro "armor," Old English searu "art"
Balto-Slavic
Old Lithuanian sėris "thread"
Hellenic
Ancient Greek εἴρειν (eírein) "to knit," "to tie"
Tocharian
A ṣurm "motive," B ṣarm 'id.'

18th cent. cerrar puerto "to take away an opportunity," "to deny."

Cerrar en falso "to lock up;" "to heal poorly, so that a wound is only superficially improved."