Q. What is a misfeature?
A program feature that eventually causes lossage, possibly because it is not adequate for a new situation that has evolved.
Since a misfeature results from a deliberate and properly implemented feature, a misfeature is not a bug. A misfeature is usually carefully planned, thinking it will “help the user.”
Many misfeatures (especially in user-interface design) arise from development reasons and personal taste rather then adhering to laws of nature and common sense.
“Well, yeah, it is kind of a misfeature that file names are limited to six characters, but we wanted to save space and we are stuck with it now.”
Source: New Hacker’s Dictionary