ne'er-do-well

Short definition from Wiktionary

Noun

1. 1
   A person without a means of support; an idle, worthless person; a loafer; a person who is ineffectual, unsuccessful, or completely lacking in merit; a good-for-nothing.
2. 2
   A person who is up to no good; a rogue.

Adjective

1. 1
   Showing the characteristics of a ne'er-do-well: indolent, worthless, or roguish.