1. To lie under or beneath; to constitute the ground work of.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• undere,
• underwrie,
• underthe,
• undergae,
• underlake,
• underly,
• undeline,
• underbie,
• undergir,
• underlei,
• undrlie,
• underli,
• underlye,
• undesoil,
• undertie,
• underunk,
• undecilic,
• undefiy,
• undecliff,
• underclif

• under it,
• underspent,
• underworld,
• undermanned,
• undersea,
• understate,
• unaddressed,
• underage,
• underbred,
• undercut,
• undercoated,
• unadorned,
• underdone,
• underwriter,
• underfelt,
• underact,
• underwear,
• undergird,
• underrate,
• underseal,
• undoer,
• underseller,
• undershrub,
• under fire,
• underspend,
• underprice,
• underived,
• underpin,
• underhanded,
• Underdahl,
• underpart,
• underlying,
• undersized,
• undertow,
• understated,
• underwrite,
• undertaker,
• underling,
• undersell,
• undervalue,
• underhill,
• underframe,
• underdress,
• underpay,
• undersoil,
• undertide,
• underdog,
• underwater,
• underexpose,
• underscore,
• undercover,
• underquote,
• underweight,
• undermine,
• undertake,
• undershirt,
• undersize,
• underbelly,
• underskirt,
• undersexed,
• underside,
• underline,
• undertone,
• under wraps,
• under,
• underarm,
• under arms,
• underfur,
• underfed,
• underway,
• underlay,
• underneath,
• undersealed,
• untier,
• undergo,
• underbid,
• unmoderated.

The adverb form of "underlie" is "underlying".

The adjective form of the word "underlie" is "underlying".

The plural form of the word "underlie" is "underlies"

The singular form of the word "underlie" is "underlies"