subunguial
/ˌsʌbʌŋˈɡwaɪəl/ or /ˌsʌbʌŋˈɡweɪəl/Definitions
1. adjective
relating to or affecting the area under the fingernail or toenail
“The subunguial infection was caused by a bacterial infection.”
2. noun
a condition affecting the area under the fingernail or toenail
“The subunguial was painful and required medical attention.”