WordNet sense 1 (existing as an essential constituent or characteristic):

built-in, constitutional, inherent, inbuilt

WordNet sense 2 (belonging to a thing by its very nature):

intrinsic, intrinsical

WordNet sense 3 (constituting the undiminished entirety; lacking nothing essential especially not damaged):

entire, intact

WordNet sense 4 (including all components without exception; being one unit or constituting the full amount or extent or duration; complete):

whole