threadless
/ˈθredlɪs/Definitions
1. adjective
without a thread or thread-like structure; smooth, unthreaded, or unnotched
“The engineer ensured the new bearing was threadless to minimize friction.”
2. adjective
relating to or resembling a thread; having a thread-like or fibrous structure
“The biologist examined the threadless pattern of the cell membrane under a microscope.”