Frannie shushed her with a forefinger to the lips.

弗兰妮把食指放在嘴唇上让她保持安静。

《柯林斯英汉双解大词典》

I made do with some peanut butter, scooped directly from the jar with a forefinger: why dirty a spoon?

我用花生酱凑合一下，直接用食指从罐子里舀出：何必还要弄脏勺子？

youdao

The navvy, swaying, presses a forefinger against a wing of his nose and ejects from the farther nostril a long liquid jet of snot.

这个苦力晃晃悠悠地用食指按住鼻翼的一边，从另一边鼻孔里擤出长长的一条鼻涕。

youdao

He seemed content with making a visual record, day after day, of that naked, statuary figure, of that slow, docile flesh, of that inexpressive face and those closed or, perhaps, fastidious eyes, of a knee bending or a breast tilting or a forefinger slowly removing a speck from a cheek.

NEWYORKER: While the Women Are Sleeping

He answers his own question by putting his thumb and forefinger together in a big round 0.

ECONOMIST: Mexico enjoys a real election campaign | The

He cleared a space on the bed and put down a little sack, and very delicately, pinching with his thumb and his forefinger, removed all the elements of a tiny feast and laid them on the bed.

NEWYORKER: A Tiny Feast