Here's what rhymes with observain.
vain vein sane fain vane feign thane main gain pain chain rain reign ln cane slain stain lane lain pane rein bane mane tain wane certaine deign skein urbane swain arraign wain brain grain plain plane strain train attain sustain ascertain drain insane profane terrain abstain crane hurricane pertain twain germane halothane inane moraine overlain sprain urethane chicane murrain obtain remain domain retain refrain champagne cocaine disdain humane regain detain ordain sugarcane arcane butane cellophane humaine appertain romaine contain explain maintain campaign entertain restrain constrain mundane coxswain retrain ingrain wholegrain reattain complain aeroplane inhumane monoplane hydroplane preordain polyurethane legerdemain windowpane foreordain reexplain demimondaine Words that almost rhyme with observain
same fame shame came name game frame flame lame tame dame maim claim blame overcame aflame defame forename became acclaim inflame disclaim rename selfsame declaim aspartame ballgame proclaim exclaim reclaim filename quitclaim counterclaim