Definition of "monopolarly"

Slow wave phase reversals between two zygomatic leads used monopolarly are often seen as such artifacts.

1947, Journal of Neurosurgery, volume 4, page 354

Cortical evoked responses are commonly recorded monopolarly by placing a single electrode wire, ball, or wick on the surface of the cortex and measuring against a distant indifferent such as an alligator clip on the cut skin edge.

1966, Joseph B. Sidowski, Experimental methods and instrumentation in psychology, page 136

It is usually recorded from electrodes on the scalp. It can be recorded bipolarly from two electrodes placed over the same part of the cortex, or monopolarly with one “active” electrode over the cortex and a second “reference” electrode on some other part of the head.

2013, Leslie B. Cohen, Infant Perception: from Sensation to Cognition: Basic Visual Processes‎