Learn how to say Remissness correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word remiss:
lacking care or attention to duty; negligent:
it would be very remiss of me not to pass on that information
late Middle English: from Latin remissus ‘slackened’, past participle of remittere. The early senses were ‘weakened in colour or consistency’ and (in describing sound) ‘faint, soft’