exosphere exosperm • exosporal · · · Info · Definitions · Characters · · exosphere · · Text Latin · · Script 9 · · Length 3 · · Syllables Definitions · · · (noun) the outermost atmospheric layer. · · Noun Definition 1 Characters · · e latin small letter e U+0065 h latin small letter h U+0068 o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 x latin small letter x U+0078