Literally: sitting like a tailor
Meaning: sitting cross-legged
Origins: In old French taileor, the one that cut the material for clothing, by extension someone that make clothes. Comes from the way the first artisans were sitting on a rug on the floor, legs crossed, this position helped them to keep their body balanced.
Examples: Plusieurs hommes assis en tailleur dégustent un café.
Several men sitting cross-legged are sipping on coffee.