Definition of "blithely"

[…] and now was hardly the time, as Stephen pointed out, to be worried about cleaning up his act, and eliminating the chemical additives and other pollutants that we’re all blithely or not so blithely feasting on, blithely since we’re healthy, healthy as we can be; so far, Ira said.

1986 November 24, Susan Sontag, “The Way We Live Now”, in The New Yorker‎

The episode also opens with an inspired bit of business for Homer, who blithely refuses to acquiesce to an elderly neighbor’s utterly reasonable request that he help make the process of selling her house easier by wearing pants when he gallivants about in front of windows, throw out his impressive collection of rotting Jack-O-Lanterns from previous Halloweens and take out his garbage, as it’s attracting wildlife (cue moose and Northern Exposure theme song).

2012 May 27, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “New Kid On The Block” (season 4, episode 8; originally aired 11/12/1992)”, in The Onion AV Club‎

So I carried on, blithely ignorant. And by the time I saw the stats, there was a 100% chance I’d got it.

2023 February 6, Hilary Osborne, “I thought knowing I had the ‘cancer gene’ would cast a shadow over my life. Now I have it, I realise how wrong I was”, in The Guardian‎