Ф-34

НА ФУФУ obsoles, highly coll PrepP Invar adv

(to do sth. ) haphazardly, without proper care, thought, attention etc

carelessly

slapdash in a slipshod (slapdash) manner.

Ему ничего важного нельзя поручать: все делает на фуфу. You can't trust anything important to him, he does everything slapdash.