Severest rhymes with:
dearest, nearest, aquarist, armbrust, barest, buttressed, dearest, deforest, direst, embarrassed, florist, forest, forrest, guitarist, interest, jurist, laforest, merest, nearest, noninterest, pendergrast, psychiatrist, purest, rainforest, rarest, reforest, terraced, tourist
Severest sounds like:
seabright, seafirst, shipwright, siebrecht, sobriquet, sparked, sprigged, sprocket, spruced, suffragette, suffragist, supercut, superoxide, supersede, superseded, suppressed