Bikini maybe excessively abbreviated all around (5)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

TO [o] (excessively) without the last letter (abbreviated), with ALL around it. Definition by example: a ring-shaped coral reef, such as the one in the Pacific Ocean known as Bikini. (The two-piece swimsuit was first introduced a few days after Bikini Atoll was used for nuclear testing; the name seems to have been a rather bad-taste joke by its designer, who hoped it would produce a shockingly explosive reaction.)