1. An adjective used to denote something especially effective at a given time. Slang originating from collectible card games: a card deemed particularly useful in a certain situation is deemed "tech," and it spread to other things.
2. A synonym for cool, due to sloppy usage of definition 1.
Both definitions are usually only used by card geeks.
Oh, man. Telling your mother that you were at a blood drive instead of out drinking was tech—now she thinks you're disoriented due to blood loss!