1. Not borrowed.

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

• ynderived,
• hnderived,
• jnderived,
• inderived,
• 8nderived,
• 7nderived,
• ubderived,
• umderived,
• ujderived,
• uhderived,
• unserived,
• unxerived,
• undeerived,
• underivedd,
• undeirved,
• underyved,
• undrivied,
• Undriveed,
• Undrvived,
• Undriived

• underlying,
• underbred,
• underneath,
• underdressed,
• underline,
• understudy,
• underseller,
• underdone,
• under wraps,
• undersea,
• underachieve,
• understaffed,
• undernourish,
• underhanded,
• underhand,
• undercoated,
• undermanned,
• underprice,
• undersurface,
• under arms,
• undershirt,
• underwater,
• underside,
• underbelly,
• underactive,
• untrimmed,
• underspent,
• unmoderated,
• underbid,
• unmodernized,
• undersoil,
• unaddressed,
• underlie,
• underworld,
• underrate,
• underbodice,
• understood,
• underexpose,
• undersized,
• undried,
• undersell,
• underweight,
• unmodernised,
• understated,
• underdress,
• understate,
• untried,
• untier,
• underdog,
• undertake,
• underspend,
• underbody,
• understand,
• underage,
• undoer,
• unadorned,
• underdown,
• underwrite,
• underivative,
• underwriter,
• under fire,
• undergird,
• undertone,
• underfelt,
• underfed,
• undertide,
• undergrad,
• underclothed,
• undervalue,
• underseal,
• underframe,
• underpart,
• underquote,
• underscore,
• undercover,
• undersealed,
• undertaker,
• undersexed,
• underskirt,
• undermine,
• undersize,
• underfur,
• Underdahl,
• undershrub,
• undergo,
• underwood,
• underwear.

The adjective form of "underived" is "underived".

The plural form of the word "underived" is "underiveds".

The singular form of the word "underived" is "underivation".