This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. (computing) Describing an action which, when performed multiple times, has no further effect on its subject after the first time it is performed.

adj. Said of an element of an algebraic structure (such as a group or semigroup) with a binary operation: that when the element operates on itself, the result is equal to itself.

adj. Said of a binary operation: that all of the distinct elements it can operate on are idempotent (in the sense given just above).

n. An idempotent ring or other structure

n. In multiple algebra, a quantity which multiplied into itself gives itself. Ordinary unity is idempotent.

adj. unchanged in value following multiplication by itself

"On your last few paragraphs, I'm not sure I get your comment about it being "idempotent" with creationist second law arguments - though I can't say I'm terribly familiar with those."

unchanged   

nullipotent    nilpotent    idempotence    unipotent   

lower-triangular    protomatter    socio-cultural    þber    regularization