From pinasubalian + -g + kalagmitan. Coined by Lupon sa Agham (Committee on Science) in the Maugnaying Talasalitaang Pang-agham : Ingles-Pilipino (Correlative Word List for Sciences : English-Filipino), published in 1969 and edited by Gonsalo del Rosario. This term fell under the Kublupon sa Sipnayan (Subcommittee on Mathematics), headed by Manuel M. Maravilla.