In well testing and production analysis it means the fluid pressure value at a certain downhole point of wellbore
The usual notation is p_{wf} whether the well is flowing or shut-in.
Unlike the original meaning of bottomhole, the bottomhole pressure may not necessarily refer to the lowest accessible point of the borehole and may refer to the sandface depth or to the pressure gauge hanging location.
See Also
Petroleum Industry / Upstream / Production / Subsurface Production / Well & Reservoir Management
Subsurface E&P Disciplines / Production Technology
[ Permanent Downhole Gauge (PDG) ]
[ Estimating Datum Pressure from downhole pressure gauge ]