Sniffen rhymes with:
kniffen, giffen, griffen, griffon, kniffen, stiffen, acetaminophen, altenhofen, carstarphen, dalfen, deafen, dextrathoraphan, dolphin, draffen, entoffen, farfen, geffen, giffen, griffen, griffon, hafen, hanifen, hyphen, ibuprofen, kniffen, lafon, ludwigshafen, mcguffin, mcmuffin, morphin, muffin, offen, often, orphan, paraffin, siphon, soften, steffan, steffen, stephan, stiffen, sutphen, syphon, tamoxifen, toughen, xenophon
Sniffen sounds like:
sampan, schoenbaum, shampine, shimbun, shinbein, shinbone, sinfonia, sunbeam, symbion, symphony