trigger finger

any finger, usually the forefinger, that presses the trigger of a gun.

either forefinger, depending on which hand is dominant.

Pathology. difficulty in straightening or bending a ring finger, caused by inflammation and thickening of its tendon.

Origin of trigger finger

First recorded in 1820–30

One little crooking of the trigger-finger and the lead had gone upon its errand.

The Master of Appleby |Francis Lynde
His trigger-finger glided inside the guard; there was a sudden wrist movement and the revolver whirled end for end.

When the West Was Young |Frederick R. Bechdolt
The speaker smoothed the barrel of his rifle with mittened hand, which had, however, a trigger-finger free.

Northern Lights |Gilbert Parker
Gripping his revolver hard, his trigger-finger steady, the corporal fired again, and another of his foes fell.

The adventures of Kimble Bent |James Cowan

Suppose that the Carolina trigger-finger slipped, as Hunter had nonchalantly admitted might happen: what then?

Slippy McGee, Sometimes Known as the Butterfly Man |Marie Conway Oemler