English
threadjacking
Blend of thread + hijacking.
Proto-Indo-European *terh₁- ‘rub’
Proto-Indo-European *treh₁-tu-s
Proto-Germanic *þrēduz ‘thread’
Old English þrǣd
Middle English thred
English thread
Today it means
noun The act of taking over an e-mail list or discussion thread with a subject unrelated to the original posting.
Language periods are conventional ranges, not dates for this word.
Etymograph / threadjacking