cough ocugh cuogh ucogh oucgh uocgh coguh ocguh cgouh gcouh ogcuh gocuh cugoh ucgoh cguoh gcuoh ugcoh gucoh ougch uogch oguch gouch ugoch guoch couhg ocuhg cuohg ucohg ouchg uochg cohug ochug choug hcoug ohcug hocug cuhog uchog chuog hcuog uhcog hucog ouhcg uohcg ohucg houcg uhocg huocg coghu ocghu cgohu gcohu ogchu gochu cohgu ochgu chogu hcogu ohcgu hocgu cghou gchou chgou hcgou ghcou hgcou oghcu gohcu ohgcu hogcu ghocu hgocu cugho ucgho cguho gcuho ugcho gucho cuhgo uchgo chugo hcugo uhcgo hucgo cghuo gchuo chguo hcguo ghcuo hgcuo ughco guhco uhgco hugco ghuco hguco oughc uoghc oguhc gouhc ugohc guohc ouhgc uohgc ohugc hougc uhogc huogc oghuc gohuc ohguc hoguc ghouc hgouc ughoc guhoc uhgoc hugoc ghuoc hguoc
Note: these 'words' (valid or invalid) are all the permutations of the word cough. These words are obtained by scrambling the letters in cough.