Referring Clues

• Thick
• None too bright
• None too brainy
• Not too swift
• Thickheaded
• Impenetrable
• Crowded
• Packed tight
• Blockish
• Not the brightest bulb on the tree
• Doltish
• Unintelligent
• Blockheaded
• Short on sharpness
• Slow on the uptake
• Like osmium, more than any other known element
• Packed
• Hardly suited for Mensa
• Concentrated
• Not the sharpest pencil in the box
• Obtuse
• Not very sharp
• A few bricks shy of a load
• Not exactly a genius
• Like a rain forest
• Tightly packed
• Like pea soup fog
• Not the sharpest tack
• Crammed
• Thick as a brick
• Thickly populated
• Slow-witted
• Hard to penetrate
• Highly concentrated
• Hard to get through
• Jam-packed
• Hardly suited for 57-Across
• Hardly sparse
• Dull
• Slow to catch on
• Hard to get through to
• Not bright
• Not at all sharp
• Like heavy fog
• Like thickets
• Like some fog
• Hard to see through
• Not too bright
• Slow
• None too swift
• Heavy, as fog
• Thickly packed
• Really crammed in
• Closely compacted
• Closely crowded together
• Tough to get through to
• Slow to understand
• Not too astute
• Compact
• Far from 22-Down
• A little on the slow side
• Cement-headed
• Like a thicket
• Overgrown
• Very thick
• Like urban populations
• Crowded together
• Not sparse
• Tough to get through
• Stupid
• Like a dumbbell
• Not Mensa material
• Like a black hole
• Like depleted uranium
• Packed with ideas, as an essay
• Practically impenetrable
• None too smart
• Heavily populated
• Dimwitted
• Not the sharpest tool in the shed
• Packed tightly
• Thick, like fog
• No rocket scientist
• Not so swift on the uptake
• Compacted
• Not getting it
• Bubble-headed
• Like dunderheads
• Thick, as fog
• Like a copse
• Thick in a couple of ways
• Not very bright
• Like pea-soup fog
• A few fries short of a Happy Meal
• Like some populations
• Scarcely bright
• Packed in tight
• Like Archie's pal Moose
• Dumb as a box of rocks
• Like rain forests
• A few bits short of a byte
• A few players short of a team
• Like a neutron star
• Close-packed
• Like a blockhead
• Hard to hack a path through
• Thickset
• Unable to get it, say
• Crammed in
• Complex
• Like urban population
• Like a pea-soup fog
• Difficult to get through
• Not exactly Mensa material
• Populous
• Hard to see through, as fog
• Dumb as a rock
• Not the brightest bulb on the Christmas tree
• Closely packed
• Not too quick on the uptake
• Heavy for its size
• Like thick fog
• Tightly compressed
• Compact and tight together
• Solid
• Firm
• Firmly packed
• Really thick
• Heavy, like some baked goods
• Thick-headed
• Thick poles in river
• Knuckleheaded
• Guolaugur Ottarsson: "___ Time"
• Sold-out show
• Like thick audience
• Crowd at big show
• Like crowd at big show
• Thick crowd
• Like sold-out audience
• Like sold-out show crowd
• Like crowd during sold-out concert
• Thick - compact
• Obtuse - impenetrable
• To scatter seed around the end of Autumn is stupid!
• Thick scattering of seed around the end of the garden
• Thick part of a wooden seat
• However stupid, one can see that private rooms have a key
• Being thick, needs to change
• Not very bright, but studies English
• Thick wooded valley around the point
• Needs (anag)
• Several rooms with one key? Stupid!
• Not very bright - needs to be properly organised
• Like mercury
• None too quick on the uptake
• Having a high specific gravity
• Jammed
• Compressed
• Dim woman lacks ego
• Needs to be close
• Thick part of wooden seat
• Take bearing in English forest - it's impenetrable
• Study some outsiders crowded together
• Somehow needs to be firm
• Clobber needs to be packed
• Thick and tightly-packed
• Close knit
• Thick part of a garden seat
• Very compact
• Thick poles embedded in water
• No thin scattering of seed around the end of the garden
• A little slow on the uptake
• Heavy, as a fog
• Thick resident in sudden seizure
• Like platinum
• Thick scattering of seed round the end of the garden
• Needs reform, being stupid
• Crowded or tightly packed
• Highly populous
• Like matted growth from garden seed
• Closely clustered
• Well-populated
• Like flourless cakes
• Possibly needs to be thick
• Thick, in more ways than one
• Being stupid, needs revision
• "Infinite" descriptor of black holes
• Many possibly seen as stupid
• ___ fog
• Thick poles set in the river
• Dull part of a wooden seat
• Like some forests and fog
• Packed in like sardines
• Fog word
• Like a thick fog
• To scatter seed around the 1st of November is stupid
• Junglelike
• Fog modifier
• ___ fog advisory
• Like flourless cake
• Hard to get through ... or get through to
• Opposite of fluffy, for a cake
• Like dumbbells
• Pretty thick
• Like the element osmium
• Like flourless chocolate cake
• Mentally slow
• Like a thick jungle
• Like a complex report
• Like pound cake
• Rather thick