The term fat finger, often in combination with "fat-finger syndrome", is used as slang to refer to making an error in or on (something) by hitting the wrong key or button, or accidental inaccuracy in the fine motor movements of one's extremities.

“胖手指”（fat finger），多以“胖手指综合征”（fat-finger syndrome）的词组形式出现，指因为按错键或按钮而犯错，或者在手工完成某项精工细活时意外出现的失误。

In general terms, for example, pressing a different button than expected on a touchscreen, or hitting two adjacent keys on a keyboard in a single keystroke during data entry (for example, buckled instead of bucked due to the L key being next to the K key on many keyboards).

最常见的就是，在触摸屏上按错键，或者按键输入的时候同时按了两个相邻的键而导致输入错误。例如，输入单词bucked的时候，因为k和l的按键相邻，而把单词输入成了buckled。

For example:

You can easily fat-finger the tiny keyboard on this device.