Stop from stepping, perhaps

• Show rudeness in traffic
• What ballroom stags do
• Interrupt a conver­sation
• Act rudely at the checkout counter
• Change partners, in a way
• Local interruption on TV
• Not wait one's turn
• Interrupt, as a dancer
• Interrupt with a shoulder tap

Wiktionary Word definitions in Wiktionary
n. (context biochemistry English) A waxy polymer of hydroxy acids that is the main constituent of plant cuticle