malapropism /malˈə-pro-pi-zm/

1. The misapplication of words without mispronunciation, from Mrs Malaprop in Sheridan's play, The Rivals, who uses words malapropos
2. A word so used

• pen friends
• penful
• penfuls
• penguin
• penguineries
• penguinery
• penguinries
• penguinry
• penguins
• penguin suit
• penguin suits
• pen-gun
• pen-guns
• penholder
• penholders
• peni
• penial
• penicillate
• penicilliform
• penicillin
• penicillinase
• penicillinases
• reboils
• reboot
• rebooted