mar·plot \ˈmärˌplät\noun Etymology:mar (I) + plot 1.: one who frustrates or ruins a plan or undertaking by his meddling < served by varmints, nitwits, and marplots — S.L.A.Marshall > 2.: one who endangers the success of an enterprise < this small marplot had discovered a great deal too much — Rudyard Kipling > • mar·plot·ry\-lä.trē\noun-es