The /Ɵ/ sound is spelled with <th> or <the>. Several contrasts arise from contrasting an ordingal number, eg tenth, with its cardinal equivalent, ten. Others come from contrasting a derived noun, e.g. warmth, from its root adjective, warm.
As /Ɵ/ is fairly rare, only occurring in 1591 words in the dictionary, this was an easy list to work out manually. The contrast is not a source of difficulty where it occurs at the start of the syllable, but is much harder when syllable-final, even for native speakers.
The density value is 13.1%. The list makes 134 semantic distinctions, a loading of 64%.
aesthetic ascetic anther anna anthers annas bath baa baths baas bathing baaing bathed baaed bath bar baths bars bathed barred bathed bard Beith be Beith bee berth burr berths burrs billionth billion birth burr births burrs both beau both bow breadth bread breadths breads deathly deli earth err earths errs eaarthed erred earthen earn earthen urn earthly early eighteenth eighteen eighth eight eighths eights eleventh eleven elevenths elevens eye-teeth Eyetie faith fey faiths face filth fill filths fills filthy filly firth fir firths firs firth fur firths furs forth for forth fore forth four fourth for fourth fore fourth four fourths fours fourteenth fourteen fourteenths fourteens Gareth Garry growth grow growths grows health hell healthy heli heath he hundredth hundred hundredths hundreds Judith Judy Keith key Keith quay loath low loathly lowly loathlier lowlier loathliest lowliest maths mass Meath me meths mess millionth million millionths millions mirth myrrh mouth mow mouths mows myths miss nineteenth nineteens nineteenths nineteens ninth nine ninths nines oath owe oaths owes oathing owing oathed owed outgrowth outgrow outgrowths outgrows overgrowth overgrow panther panner panthers panners pathless parlous Perth purr plaything playing rethink re-ink rethinks re-inks ruth roo ruth rue seventeenth seventeen seventeenths seventeens seventh seven sevenths sevens sheath she sixteenth sixteen sixteenths sixteen sixth six sleuth slew sloth slow sloths slows sooth Sue south sow struth strew teeth tea teeth tee tenth ten tenths tens tenths tense thaw awe thaws awes thaw or thaw ore thaws ores theft eft thefts efts theory eerie thews use thieve eve thieves eves thigh eye thighs eyes thin in thin inn thins inns think ink thinks inks thinking inking thinner inner thinners inners thirteenth thirteen thirteenths thirteens thistle istle though owe thought ought thousandth thousand thousandths thousands thrash rash thrashes rashes thrasher rasher thrashers rashers thread read thread red threads reds threat ret threats rets threw roo threw rue thrill rill thrills rills throat rote throat wrote throb rob throbs robs throbbing robbing throbbed robbed throe roe throes roes throe row throes rows throne roan thrones roans throng wrong throngs wrongs thronging wronging thronged wronged through roo through rue throve rove throw roe throws roes throw row throws rows thrown roan thrum rum thrush rush thrushes rushes thrust rust thrusts rusts thrusting rusting thunder under thwack whack thwacks whacks thwacked whacked thwacking whacking thwacks wax thwart wart thwarts warts trillionth trillion trillionths trillions truth true umpteenth umpteen untruth untrue warmth warm wealth well wealthy welly worth were wraith ray wraiths rays youth you youths use
John Higgins, Shaftesbury, December 2010.