You can read a book about agile development or Google any agile term, and the definition will most likely be in context of an engineering practice or reference to code. The basic concepts in marketing are very similar, but the ways they are implemented can be very different. Below are my translations.
 
Iteration/Sprint – A fixed period of time, usually 1-4 weeks, in which work is planned, managed and delivered. Agile teams commit to working on a set of prioritized stories and nothing else during this time period – nice in theory, not always possible in practice, especially in marketing.  In order to manage fire drills or other work, you can do one of two things – build time into your iteration, or get very disciplined at saying "We'll put it in the backlog".

Backlog – Prioritized list of work items (stories) not currently scheduled into the iteration. As you well know, marketing priorities are often changing (monthly, weekly, even daily) so backlog management can be challenging.

Story/Backlog Item /Feature – Most often in agile software development, it's code that delivers specific functionality and provides business value (What is a feature?). In marketing, the idea of business value still applies, but often times is thought of in terms of deliverables – collateral, online content, events, ads, etc.

User Story – A way to define a story from the perspective of the end user. The typical format is “As a (user) I want (requirement) so that (goal)”. This format works well to describe feature/functionality in software development practices, but we haven’t found it as useful on our marketing team. We structure our stories based on define, design or deploy phases (more to come on this later).

Estimation – The process teams use to determine the size of a story, usually through Story Points, ideal days or t-shirt sizes (small, medium, large, extra-large). The work associated with a story must be well defined/understood in order to accurately estimate. Keep in mind who outside of the marketing team is involved with a story -- even though you don’t include their time in the estimate, these stories usually take more time/effort.

Story Point – A unit of measurement used to estimate the work/effort/complexity of a story in order to give it a comparable size. Typically a 1 is twice as big as a 2 in terms of complexity. The challenge in marketing is that some stories might be “easy” but take a long time and others might be “hard” but not take very much time (more on this one too).

Task – The small, individual work items that comprise a story. Typical tasks in marketing include brainstorming, outlining, drafting, feedback loops, proofing, dry runs, pushing live, sending out.

Taskboard – A visual information radiator which is a fancy name for a whiteboard (physical or online), or wall chart with index cards, or sticky notes to track the status of tasks. Have fun creating a taskboard, but don’t over think it.

Defect – In agile software development, a defect or bug refers to an unexpected behavior in a feature often caused by a problem with the code. In marketing, defects are more likely to come in the form of typos, broken links, unclear messaging, etc.

Impediment – Anything that prevents agile teams from getting their work done. Common marketing impediments include too much feedback (often unsolicited), budget constraints, outside vendors and external dependencies.

Done – This deserves its own post (or even series of posts), but for now, done means that the tasks required to deliver the agreed upon value of a story are completed and the product owner has accepted the story. Life is much easier when done is defined at the time the story is planned and estimated.

These are only a few agile terms you’ll need to (re)define for a successful agile implementation in marketing. Have your own software-to-marketing agile translations? Please share.