Senescence rhymes with:
evanescence, luminescence, evanescence, luminescence, acquiescence, adolescence, coalescence, convalescence, essence, evanescence, luminescence, obsolescence, phosphorescence, quintessence
Senescence sounds like:
samsung, samsung's, sansing, schmiesing, schmoozing, sensenig, sensing, sequencing, shenanigans, simkins, singing, sinking, smacking, smashing, smoking, smoking's, smoshing, smugness, snacking, snagging, snaking, sneaking, sneezing, snoozing, snugging, squeamishness, ssangyong, sunshine's, swensen's, swinging