foresightlessadj.

/ˈfɔːsʌɪtlɪs/Etymology: formed as foresight n. + -less suffix.
Derivatives
the mind > attention and judgement > inattention > [noun] > lack of foresight
1880 G. MacDonald 65 Lost in oblivion and foresightlessness.
This entry has not yet been fully updated (first published 1897; most recently modified version published online December 2018).