gas balloon (noun) hot-air balloon: lighter-than air craft
Sinonime: built-in,
chronic,
confirmed, congenital, constitutional, deep-seated,
fixed,
fundamental, hereditary, implanted, in the blood, inborn, inbred, inbuilt,
indelible, indwelling, ineradicable, inherent, innate,
intrinsic,
inveterate,
rootedAntonime: superficial,
surface