Lifelines rhymes with:
airline's, airlines, airlines', baselines, bloodlines, caroline's, coastlines, dateline's, datelines, deadlines, enterline's, esterline's, felines, frontline's, guidelines, headlines, hemlines, hotlines, moneyline's, nightline's, nightlines, online's, outlines, pipeline's, pipelines, pipelines', sidelines, skylines, smithkline's, storylines, strandlines, underlines, villines
Lifelines sounds like:
labeling, lablanc, leblanc, leveling, liebling, lifelong, liveliness