It means decimal, in Hindi (and related languages)
I remembered it yesterday, out of the blue. And made a connection about it that I hadn’t for decades.
I learnt this word not in a classroom, but watching TV. DD (Doordarshan) was the only TV channel we use to receive while growing up. The weather presenter on DD news used to pronounce temperatures in Hindi, using दशमलव for decimal. E.g. बारह दशमलव तीन to say 12.3 (बारह is hindi for 12, and तीन means 3).
Later cable TV arrived at my middle-class house in my small, dusty town. We could now watch NDTV News for good news in English, and Zee News had news presented in Hinglish as their USP for a while. DD was soon forgotten, and only remembered when revisiting memories of childhood.
The connection I made yesterday, something that should’ve been obvious all those decades ago was that दशमलव just means decimal. And I didn’t even arrive at this connection from the most obvious route – दश means 10.
I arrived from the phonetic route – द (D) – श (C) – म (M) – ल (L) – व.
I wonder if they still read the news in Hindi on DD, and if they still use दशमलव when giving the temperature readings :)