Verses with the word carelessly in the Old Testament (3 verses):

Isaiah 47:8
Therefore hear now this, thou that art given to pleasures, that dwellest carelessly, that sayest in thine heart, I am, and none else beside me; I shall not sit as a widow, neither shall I know the loss of children:

Ezekiel 39:6
And I will send a fire on Magog, and among them that dwell carelessly in the isles: and they shall know that I am the LORD.

Zephaniah 2:15
This is the rejoicing city that dwelt carelessly, that said in her heart, I am, and there is none beside me: how is she become a desolation, a place for beasts to lie down in! every one that passeth by her shall hiss, and wag his hand.