• understans,
• understaken,
• understads,
• understairs,
• understandes,
• understants,
• understat,
• understimates,
• understones,
• understaded,
• understane,
• understatd,
• understatnds,
• understater,
• understateds,
• understaies,
• understaiers,
• understaires,
• undestairs,
• Understayrs

• underpants,
• underside,
• unaddressed,
• understate,
• underspend,
• undercoat,
• underarm,
• underdress,
• underframe,
• underage,
• undertake,
• undergird,
• underfur,
• undersize,
• understood,
• underestimate,
• understatement,
• undercharge,
• underquote,
• underwriter,
• underpart,
• underpay,
• underwear,
• undershirt,
• underwrite,
• underboss,
• under wraps,
• underlay,
• undersexed,
• undersell,
• underclassman,
• under way,
• underact,
• undersized,
• undervalue,
• underfoot,
• under that,
• underspent,
• Underdahl,
• underdrawers,
• underway,
• underlie,
• underhand,
• undersoil,
• underrate,
• unmoderated,
• understandable,
• undercut,
• underivative,
• underskirt,
• undercurrent,
• undergrad,
• undersign,
• underactive,
• understructure,
• undersealed,
• undershrub,
• understanding,
• undergraduate,
• underscore,
• understand,
• understandably,
• undertaker,
• underpass,
• understaffed,
• undersea,
• underdressed,
• undereducated,
• under arms,
• underseal,
• under it,
• undershot,
• undercoated,
• underclass,
• underfelt,
• undershoot,
• underseller,
• understock,
• understated,
• under attack,
• underplay,
• undersurface,
• underslung,
• understudy.

The plural of the "understates" can be the "understates".

The singular of the "understates" can be the "understatement".