An oily or waxy whisky offers a viscous, coating mouthfeel rather than a light, watery texture. This tactile sensation usually comes from specific distillation practices and the retention of long-chain esters or heavy oils, frequently compared to beeswax, candle wax, or gentle oil. 

Glenlossie tends to have more consistent oiliness for me, almost exist in all the single cask bottlings. Pulteney, often mistaken as a whisky with only the saltiness and brine, but I has a oily body to it.