can be used to describe something with attempts to appear slick, however in truth is viewed upon in a very slimey way. e.g. a paper thin beard running accross ones jaw line. this phrase can also be used to describe ones actions when attempting to appear "smooth" or "seductive", but resulting in a very crude and sleazy representation of themselves.
a man notices another man dressed up in a tacky suit with slicked back hair, grinding on slutty looking women in a club and exclaims: "look at that slimline cunt!"