மழை
மழை (maḻai) is the ordinary Tamil word for rain, and the Madras Tamil Lexicon shows how much ordinary work it does. Under one headword it carries a field of senses: rain first, glossed as water that pours from cloud; then cloud itself, the water-laden cloud; then water, blackness, coolness, and abundance. The word does not distinguish the rain from the cloud that holds it or the coolness it leaves behind. These are not metaphors stacked on a literal core. They are one phenomenon named once.
That refusal to separate is the entry’s argument. When Valluvar writes பெருமழைக்கண் (peru-maḻai-k-kaṇ) in Kuṟaḷ 1239, he means an eye cool and full like the rains, and the lexicon files this under the coolness sense of மழை. Around this centre sit terms that are not interchangeable with it: கார் (kār), the black monsoon cloud; மாரி (māri), the whole drenched season; தூறல் (tūṟal), drizzle. மழை is the unmarked term the others are glossed against.
Its place in the literary cosmos is unambiguous. The Tirukkuṟaḷ opens by invoking God. Its second chapter, before renunciation, before charity, before virtue itself, is வான்சிறப்பு (vāṉ ciṟappu), the excellence of rain. The title teaches the field in miniature: it uses வான் (vāṉ), sky, to mean rain, the same metonymy that lets மழை mean cloud.
Across the chapter, rain is called அமிழ்தம் (amiḻtam), ambrosia: the food that feeds eaters and is itself drunk. Withhold it and neither charity nor penance can stand. Even divine festivals fail without it. Tamil places rain after God because rain is the first condition under which human life can become ethical.
The word reaches even into the measure of a life. In Kuṟaḷ 55, the devoted wife is one of whom it is said பெய்யெனப் பெய்யும் மழை (peyyeṉap peyyum maḻai): if she says “rain,” rain falls. From the physics of condensation to the ethics of the household, மழை names it all, and Tamil never felt the need to split it apart.
Etymology phylogeny
Time runs left to right. Solid lines mark descent; dashed lines mark semantic borrowing.