Where does “கோட்டயம்” come from?

கோட்டயம் (Tamil) comes from Malayalam കോട്ടയം, from Malayalam അകം, from Sanskrit अक, from Proto-Indo-Aryan *ákas.

Ancestry of “கோட்டயம்”, step by step

StepLanguageWordMeaning
1Malayalamകോട്ടയം—
2Malayalamഅകംinside
3Sanskritअकpain, unhappiness
4Proto-Indo-Aryan*ákas—
Every word from Proto-Indo-Aryan *ákas →Every word from Sanskrit अक →Every word from Malayalam അകം →