At her best, Lily Allen operates just at the edge of a crowd, slyly and snidely passing judgment from a safe distance.

That sense of remove remains on Sheezus, her overdue third album, but it's curdled.

She's no longer an observer; she's an outsider longing to be inside.

Blame it on her extended hiatus.

Allen lay silent for a half decade, choosing to pursue a family life instead of the pop charts, but now that she's primed for a comeback, she's ready to ruffle some feathers, baiting Kanye West with her album title, sweetening M.I.A.'s style for "Air Balloon," and taking swipes at Rihanna, Katy Perry, Beyoncé, Lorde, and Lady Gaga on the album's title track.

The subtext is clear: Allen is no provincial pop star; she belongs in the big leagues.

Based on her two previous albums -- her 2006 debut Alright, Still and its 2009 sequel It's Not Me, It's You -- this claim to the throne wouldn't seem like a stretch, but unfortunately Sheezus is pretty thin gruel.

Occasionally, there are glints of Lily's satirical swagger and casual craft, but Sheezus often teems with an unseemly defensiveness that sours the entire proceedings.

It's there when Allen simultaneously sneers at and co-opts modern R&B ("Silver Spoon," "Hard Out Here"); it's there when she taunts other stars and also when she writes too many songs about her husband, warning all other females to not give him so much as a second look ("L8 Cmmr").

Many of these songs falter on their specificity; she's traded incisive commentary for pedantic details paired with music that winds up diminished by her weariness.

Talented as she is, Allen does indeed rally at unexpected moments -- "Insincerely Yours" slides along to a yacht-soul groove, "Life for Me" cleverly twists Vampire Weekend's Graceland obsessions, and although the target of an Internet troll is beneath her, the barbs on "URL Badman" are at least sharpened -- but these songs only put the rest of Sheezus in dreary relief.