first finger

基本解释

"If you want to say 'okay', don't make a circle with your thumb and first finger, " the woman announced.
“如果你们想说‘同意’，不要用拇指和食指做成一个圈儿，”那位女士大声说道。
If the man had pointed with his first finger while he was in Brunei, everyone would have thought that he was very rude.
在Brunei，如果那人用第一个手指指着的话，那人人都会认为他很不礼貌。
putclub.com
Objective To observe the effect of ulnaris artery island flap of middle finger in repairing first finger defect of soft tissue.
目的观察以中指尺侧动脉岛状皮瓣修复拇指软组织缺损创面的效果。
kns50.chkd.cnki.net

First, finger pointing between left and right is off the mark in this case.
FORBES: Expert: Loughner Rants Sound Like Sovereign Citizen Beliefs
The barred G chord in the third position will subsequently be noted with a 3 listed on the low E string, and as you can tell in the picture above, the accompanying bar will elevate on a string-by-string basis to provide a slight visual cue as to how far from the first-finger fret your other digits go.
ENGADGET: Rock Band 3 Pro guitar preview: the guitarist vs. the guitar hero
In 1947 Gottlieb began a revolution with Humpty Dumpty, the first game with finger-operated flippers.
FORBES: Magazine Article