be on home ground—(also: be on one’s own ground)
1. be in the area where one works or lives (with the implication that it makes a person feel confident and secure):
- I was sad to see Argentina lose on penalties. They were doing pretty well considering the Germans were on home ground.
2. be competent in a subject because one is thoroughly familiar with it (with the implication that it makes a person feel relaxed and comfortable):
- Here he is on home ground, spinning webs of excellent dialogues around incidents, holding the spectator spellbound. Here he is at his professional best.
play away from home—(coll.) have an affair on the side:
- Pink allegedly agreed that Carey could “play away from home” while she is on tour.