a battle-cruiser

active participation / being active / being energetic / being lively / being thriving / being successful / flourishing / making a big contribution / playing an active role / making a great achievement / contributing greatly / being productive

to be active (in), to participate actively (in)

mainstay, leader, flagship, main one

battleship (warship)

(military) navy

go around, travel around / circle, surround / return, repeat / concern (usually in the form of を + めぐる or めぐって)

turn, round

go around

circumference / tour / circulation