Real Dictionary

turf
Someone's turf is the area which is most familiar to them or where they feel most confident.
Turf is short, thick, even grass.
countable noun: A turf is a small rectangular piece of grass which you lay on the ground in order to make a lawn.

turf in American English
a surface layer of earth containing grass plants with their matted roots; sod; sward
to cover with turf
noun: a layer of matted earth formed by grass and plant roots

turf in British English
noun: the surface layer of fields and pastures, consisting of earth containing a dense growth of grasses with their roots; sod