1. A step in a staircase or sequence that is absent, absent, or not present where it should be
He tripped over the missing step on the basement stairs.
Ele tropeçou no degrau faltante das escadas do porão.
2. A gap or omission in a logical sequence, process, or argument
There's a missing step in your reasoning that doesn't connect these two conclusions.
Há um degrau faltante no seu raciocínio que não conecta essas duas conclusões.