rachitic

adjective2

1. •
   Of or pertaining to, or affected by, rickets (“a disorder of infancy and early childhood due to a deficiency of vitamin D, causing soft or weak bones”).

   • Nor was there time to do much more than distribute some sweet to the pallid rachitic children. — 1982
2. •
   (figurative) In a precarious or weak condition; likely to break down or collapse; feeble, rickety.

   • Gumbril Senior occupied a tall, narrow-shouldered and rachitic house in a little obscure square not far from Paddington. […] It was a prematurely old and decaying house in a decaying quarter. — 1923