noun
kern
In typography and computing, the part of a letter that extends beyond its bounding box, or the adjustment of spacing between specific character pairs.
フォントの左右突出部を調整すると、文字の間隔が自然に見える。
Adjusting the font's kerns makes the spacing between characters look natural.
この書体では、「A」と「V」の間に左右突出部が設定されている。
In this typeface, a kern is set between 'A' and 'V'.
カーニング is the more common loanword for the process of kerning, while 左右突出部 is a technical Japanese term for the kern itself or the protruding part.
Compound of 左右 (left and right) + 突出部 (protruding part), describing the part of a glyph that extends sideways.