In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+03C7 (GREEK SMALL LETTER CHI).
\bbalpha\bbbeta\bbchi\bbdelta\bbDelta\bbdotlessi\bbdotlessj\bbepsilon\bbeta\bbgamma\bbGamma\txtbfbbchi
\txtbfbbchiSymbol
The χ symbol (Greek small letter chi, U+03C7), written as \txtbfbbchi in LaTeX text mode.