1. My grandmother is still active and sharp-minded even though she is an octogenarian.
（我的祖母虽然已经80多岁了，但仍然活跃并头脑敏锐。）

2. The party was filled with octogenarians who danced and celebrated late into the night.
（这个派对上充满了跳舞和庆祝的八十多岁的人。）