Ash used the term "Groovy" (whatever that means) only in these instances:
1- ED2. After he created the Chainsaw Arm and the "Boomstick". Ready to fight. 2- ARMY. After he created the Iron Hand. Ready to fight. 3- At the very end of Episode 1/Season 1 (AvED), when he's 100% ready to embrace the fight with the Kandarian Demon again. Along with Kelly and Pablo. 4- At the very end of Episode 10/Season 3 (AvED), when he's 100% ready to drive the Oldsmobile in the post-apocalyptic future and face his destiny. Along with Lexx (the female warrior).