debilityn.

debilitydebility: [15] Despite the passing similarity, debility has no connection with ability. It comes via Old French debilite from Latin dēbilitās, a derivative of the adjective dēbilis ‘weak’. This was a compound formed from the prefix de- ‘not’ and a second element meaning ‘strong’, represented also in Sanskrit bálam ‘strength’, Greek beltíon ‘better’, and Old Slavic bolij ‘larger’ (ultimate source of bolshevik).debility (n.)early 15c., from Middle French debilite (Modern French débilité) or directly from Latin debilitatem (nominative debilitas) "a laming, crippling, weakening," from debilis "lame, disabled, crippled," figuratively "weak, helpless," from de- "from, away" (see de-) + -bilis "strength," from PIE root *bel- (see Bolshevik).