ระดับ

Possibly from Old Khmer ltāp, ltap (“to occur one after another”), corresponding to Modern Khmer រដាប់ (rɔɔrɔdap, “to be in close alignment”); extended as laṃtāp, laṃtap (“order, sequence, series; to arrange in orders, sequences, or series; etc”), corresponding to Modern Khmer លំដាប់ (lumdap), from which Thai ลำดับ (lam-dàp) was derived.