In a field-effect transistor: the meeting of the two non-conducting depletion layers that border the channel, such that little further increase in current is achieved by increasing the drain voltage.
Origin
1950s. From to pinch off.
Definition of pinch-off in US English:
pinch-off
nounˈpɪn(t)ʃɒf
Electronics
In a field-effect transistor: the meeting of the two non-conducting depletion layers that border the channel, such that little further increase in current is achieved by increasing the drain voltage.