Permanents

noun

1. A chemical hair treatment imparting or removing curliness, whose effects typically last for a period of weeks; a perm.
2. Given an n \times n matrix a_{ij} \,, the sum over all permutations \pi \, of \prod_{i=1}^n{a_{i\pi(i)}}.
3. (trading card games) A card whose effects persist beyond the turn on which it is played.