osteomalacia
noun
os·te·o·ma·la·cia ˌä-stē-ō-mə-ˈlā-sh(ē-)ə 
: a disease of adults that is characterized by softening of the bones and is analogous to rickets in the young
Example Sentences
Recent Examples on the Web Without enough of it, bones can become thin, brittle and misshapen, causing a condition called rickets in children and osteomalacia in adults. 
Liz Szabo, The Seattle Times, 20 Aug. 2018
Liz Szabo, The Seattle Times, 20 Aug. 2018 Word History
Etymology
New Latin, from oste- + Greek malakia softness, from malakos soft — more at mollify
First Known Use
1790, in the meaning defined above
Medical Definition
osteomalacia
noun
os·teo·ma·la·cia ˌäs-tē-ō-mə-ˈlā-sh(ē-)ə
: a disease of adults that is characterized by softening of the bones and is analogous to rickets in the young