Definition of "pluckily"

He was loudly praised for sticking so pluckily to his self-imposed task, and to this day, though it is thirteen years ago, the diggers on the Australian coast talk of the voyage of the Springbok and speak gratefully of the man who helped to save her.

1887, Harriet W. Daly, Digging, Squatting, and Pioneering Life in the Northern Territory of South Australia, page 181

Once, one of the Bats, having seized a large and powerful T. pronuba, brought its feet so far forward that it fell over on to its back, but pluckily held the moth in its pouch until it was secured.

1899, Charles Oldham, “The mode in which Bats secure their prey”, in The Zoologist, volume 3, number 700, page 472/473

Herb was initially overcome by Jakarta ('The impressions of noise, chaos, tremendous crowdedness and I suppose whitelessness were perhaps the strongest, and I felt something of a stranger') and faced with the familiar conundrum ('again the sensation of the thousands of hungry people all around –happy looking often, pluckily cheerful but in fact hungry –is strange and upsetting'), but he quickly slipped into the volunteer lifestyle with relish, borrowing a bike from Soewarto, a friend from Kempen, and spending a lot of his time with volunteers, including Lance Castles and John Gare.

2011, Jemma Purdey, From Vienna to Yogyakarta