keen (n.)
- acid
- active
- acute
- agog
- alert
- arctic
- ardent
- astringent
- avid
- awake
- bad
- bark
- bellow
- bitter
- blare
- blubber
- boom
- boss
- bray
- bright
- buggy
- bully
- burning
- buzz
- cackle
- cant
- caterwaul
- caustic
- chant
- chirp
- cold
- coo
- cool
- cordial
- coronach
- corroding
- corrosive
- crackerjack
- creak
- crisp
- crow
- cry
- cunning
- cutting
- dandy
- deep
- delicious
- dirge
- divine
- drawl
- droll
- drunk
- ducky
- dynamic
- eager
- earnest
- elegy
- eulogy
- extreme
- fab
- fine
- flaming
- flute
- forward
- freezing
- funny
- gasp
- gay
- gear
- glowing
- great
- groan
- growl
- grunt
- heavy
- hiss
- hot
- howl
- howling
- hyperborean
- icy
- itching
- jeremiad
- knell
- lament
- lamentation
- lilt
- living
- mean
- moan
- monody
- mordant
- mumble
- murmur
- mutter
- neat
- nipping
- okay
- outcry
- pant
- panting
- peachy
- percipient
- pinching
- pipe
- piping
- plaint
- pointed
- prompt
- quick
- raw
- ready
- requiem
- ripping
- roar
- rough
- rum
- rumble
- salt
- scream
- screech
- screeching
- sensitive
- set
- sharp
- shriek
- shrieking
- sigh
- sing
- skirl
- smacking
- smart
- smashing
- snap
- snarl
- snort
- sob
- solid
- sorrow
- sour
- spanking
- sparkling
- specific
- splitting
- squall
- squawk
- squeak
- squeal
- stinging
- stringent
- strong
- swell
- tart
- thin
- threnody
- thunder
- tirade
- tough
- trumpet
- twang
- ululation
- vital
- wail
- wailing
- warble
- warm
- weep
- whimper
- whine
- whisper
- whistle
- whistling
- wise
- withering
- wizard
- yap
- yell
- yelp
- yowl
keen (v.)
- ablaze
- acerbate
- active
- afire
- alert
- alive
- animate
- apt
- awake
- bad
- bark
- bawl
- bellow
- bemoan
- bewail
- bitter
- blare
- blat
- blubber
- boom
- boss
- bray
- breathe
- brisk
- bully
- buzz
- cackle
- cant
- caterwaul
- chant
- chirp
- cold
- coo
- cool
- creak
- crisp
- crow
- cry
- deep
- deplore
- divine
- drawl
- elegize
- exclaim
- fab
- fine
- flute
- forward
- gasp
- gear
- grieve
- groan
- growl
- grunt
- hiss
- howl
- knell
- lament
- lilt
- mean
- moan
- mourn
- mumble
- murmur
- mutter
- okay
- outcry
- pant
- passionate
- pipe
- prompt
- raw
- ready
- repine
- roar
- rough
- rum
- rumble
- salt
- screak
- scream
- screech
- set
- severe
- sharp
- shriek
- shrill
- sibilate
- sigh
- sing
- skirl
- skreigh
- smart
- snap
- snarl
- snort
- sob
- sorrow
- sough
- sour
- squall
- squawk
- squeak
- squeal
- swell
- tart
- thin
- thunder
- trumpet
- twang
- ululate
- wail
- warble
- warm
- weep
- whimper
- whine
- whisper
- whistle
- wise
- wrawl
- yammer
- yap
- yawp
- yell
- yelp
- yowl
keen (adj.)
- ablaze
- absorbing
- acerb
- acerbic
- acid
- acidic
- acidulent
- acidulous
- acrid
- acrimonious
- active
- acute
- adroit
- afire
- aggressive
- agile
- agog
- alacritous
- alert
- algid
- alive
- animate
- animated
- anxious
- apt
- arctic
- ardent
- astringent
- astute
- athirst
- attentive
- avid
- awake
- bad
- bang-up
- biting
- bitter
- bleak
- bonzer
- boreal
- boss
- brainy
- breathless
- bright
- brilliant
- brisk
- brumal
- buggy
- bully
- burning
- buzz
- canny
- cant
- caustic
- chant
- clever
- cold
- cool
- cordial
- corking
- corrosive
- crafty
- creaky
- crisp
- cunning
- cutting
- dandy
- deep
- delicious
- delirious
- desirous
- detailed
- devoted
- dexterous
- discerning
- discriminating
- discriminative
- distinct
- distressful
- distressing
- divine
- double-edged
- drastic
- droll
- drunk
- dynamic
- eager
- earnest
- edged
- energetic
- enterprising
- enthusiastic
- excessive
- excited
- excruciating
- exorbitant
- exquisite
- extravagant
- extreme
- exuberant
- fab
- facetious
- featheredged
- febrile
- fervent
- fervid
- fevered
- feverish
- fierce
- fiery
- fine
- fired
- flaming
- flushed
- forceful
- forcible
- forward
- frigid
- funny
- furious
- gay
- gear
- gelid
- gifted
- glacial
- glorious
- glowing
- great
- grievous
- groovy
- harsh
- heartfelt
- hearty
- heated
- heavy
- hibernal
- hiemal
- hot
- howling
- humorous
- hunky-dory
- ice-cold
- icelike
- icy
- immoderate
- impassioned
- impatient
- impetuous
- incisive
- inclement
- indelible
- intelligent
- intemperate
- intense
- intoxicated
- irritating
- itching
- jesting
- jocose
- jocular
- joking
- kinetic
- knifelike
- lively
- living
- lusty
- mean
- mettlesome
- moan
- mordacious
- mordant
- neat
- nifty
- nimble
- nipping
- nippy
- nobby
- numbing
- nutty
- okay
- outrageous
- painful
- pant
- passionate
- peachy
- penetrating
- peppy
- perceptive
- percipient
- perfervid
- perspicacious
- piercing
- pinching
- piquant
- poignant
- pointed
- profound
- prompt
- pungent
- quick
- quick-witted
- raw
- ready
- red-hot
- reedy
- rigorous
- ripping
- robust
- rough
- rum
- salt
- salty
- sarcastic
- sardonic
- scathing
- scintillating
- scorching
- screaky
- screechy
- scrumptious
- searing
- sensitive
- set
- severe
- sharp
- sharp-sighted
- sharpened
- shrewd
- shrill
- sing
- slap-up
- sleepless
- sleety
- slushy
- smart
- smashing
- snappy
- solid
- sour
- spanking
- sparkling
- specific
- spiffing
- spiffy
- spirited
- splitting
- sprightly
- squeaking
- squeaky
- stabbing
- steaming
- steamy
- stinging
- stone-cold
- strenuous
- strident
- stringent
- strong
- stunning
- swell
- talented
- tart
- thin
- thirsty
- tough
- trenchant
- unblinking
- unconscionable
- unmistakable
- unrestrained
- unsleeping
- vehement
- venomous
- vibrant
- vigorous
- violent
- virulent
- vital
- vitriolic
- vivacious
- vivid
- wailing
- wakeful
- warm
- whimsical
- wide-awake
- wintery
- wintry
- wise
- withering
- witty
- wizard
- zealous
- zestful
- zesty
- zippy
