Where does “PL/SQL” come from?

PL/SQL (English) comes from English pl, from English plural, from Middle English plurelle, from Old French plurel, from Latin plūrālis, from Latin plūs, from Old Latin plous, from Proto-Indo-European ploh₁is-.

Ancestry of “PL/SQL”, step by step

PL/SQL traces back through two separate lines of ancestry.

via English pl

StepLanguageWordMeaning
1EnglishplAbbreviation of plural; Abbreviation of place
2EnglishpluralConsisting of or containing more than one of...
3Middle Englishplurelleplural
4Old Frenchplurelplural
5Latinplūrālisplural
6Latinplūsmore; more of
7Old Latinplous
8Proto-Indo-Europeanploh₁is-

via English SQL

StepLanguageWordMeaning
1EnglishSQLInitialism of Structured Query Language;...
Every word from Proto-Indo-European ploh₁is-Every word from Old Latin plousEvery word from Latin plūs