This list consists of around 150 very short words, very obscure, each with only 3 letters. While you are not likely to use any of them in daily conversation. Who don't use in a Scrabble game these tiny creatures.
Word/ Definition
aba/ garment of camel or goat hair; camel or goat-hair fabric
abb/ yarn used for warp
aby/ to make amends; atone; pay a penalty
ait/ small island in lake or river
ala/ membranous outgrowth on a plant or animal
alb/ long white robe worn by priests
alk/ sap or resin from turpentine trees
alt/ high musical tone
ama/ a Japanese pearl-diver
ana/ in equal quantities
ard/ plough used to scratch top surface of soil
awn/ beard or similar bristly growth on stalk of grain
bar/ unit of pressure of one million dynes per square centimeter
bee/ hardwood on either side of bowsprit through which forestays are reeved
bel/ unit of noise intensity equal to ten decibels
bis/ twice; in two places
bot/ larva of a botfly that infests horses
cep/ brown edible mushroom
cog/ single-masted, square-sailed ship with raised stern
col/ depression or pass in a mountain range
cwm/ valley or glen
dag/ dirty tatted tuft of sheep's wool
dah/ short heavy Burmese knife
dal/ a dried legume, such as lentils, beans or peas
dap/ to dip gently into water; to fish with a surface fly
daw/ simpleton; bird of the crow family
dit/ poem; words of a song
dol/ unit for measuring intensity of pain
dop/ copper cup for holding a diamond while cutting it
eft/ again; afterwards
eft/ newt
eke/ in addition; also; likewise
ell/ old unit of length equal to 45 inches
ere/ before
erg/ unit of work measuring force of one dyne applied over one centimeter
eth/ old English letter for voiced 'th' sound
fid/ conical wooden pin used to splice strands of rope
fie/ expression of disgust or disapproval
fub/ to put off; to fob
fug/ hot; close; smoky state of atmosphere
gad/ to wander about idly or in pursuit of pleasure
gal/ unit of acceleration of one centimeter per second per second
gar/ mild oath
gat/ opening or strait between two sandbanks
gib/ wedge-shaped piece of metal that holds another in place
gid/ brain disease suffered by sheep
gig/ light two-wheeled one-horse carriage
hoc/ card game, now obsolete
hod/ V-shaped trough for carrying bricks or mortar on the shoulders
hoy/ large one-decked boat
ife/ tropical African fibrous plant
iff/ if and only if
ist/ one who holds to an 'ism'
ivi/ Tahitian chestnut tree
jib/ small triangular sail extending from the head of the foremast
jow/ to ring a bell; a stroke of a bell
jud/ mass of coal ready for final removal
jug/ sound of the nightingale
jus/ law; legal right
keb/ ewe that gives birth to stillborn lamb
ked/ wingless fly that feeds on livestock
kef/ state of dreamy or drug-induced repose
kep/ to catch an approaching object or falling liquid
ket/ carrion; matted wool
kex/ dry hollow plant stalk
kif/ drug like marijuana smoked in North Africa
kip/ skin of a young animal
kip/ unit of weight equivalent to 1000 pounds
kir/ drink of black currant syrup and white wine
kit/ a small pocket violin
kop/ bank of terracing at a football field
lac/ dark red transparent resin used to make shellac
lar/ local god of a house
lea/ arable land left fallow or used for pasture
lev/ monetary unit of Bulgaria
ley/ mystical straight line between features of landscape
lux/ unit of illumination equal to one lumen per square meter
mel/ honey
mew/ to shed, moult or change
mho/ unit of electrical conductance
mil/ unit of 1/1000 inch used for measuring thickness of wire
mim/ prim, demure
mon/ Japanese family crest
mor/ humus layer formed by slow decomposition in acidic soil
mow/ to make a grimace
neb/ bird's beak
nef/ ornamental stand in shape of ship for holding salt or cutlery
nim/ to steal; to pilfer
obi/ broad sash worn with a kimono
ord/ point of a weapon; a beginning
orf/ viral infection of sheep
ort/ scrap of food; morsel
pam/ card game in which jack of club has highest value
pax/ tablet decorated with sacred figure and kissed by participants in mass
ped/ naturally formed mass or aggregate of soil
per/ through; according to; by means or agency of
pro/ in favour of; for
pug/ ground clay mixed with water
puy/ small volcanic cone
pyx/ box or vessel in which coins or consecrated Eucharist are kept
qat/ leaves chewed or brewed in tea as a stimulant
qua/ in the capacity of
ras/ headland
rep/ plain-woven fabric with crosswise ribs
ret/ to expose to moisture; to soak; to soften by soaking
rev/ to run an engine before bringing it into use
ria/ normal drowned valley; long wide creek
roc/ enormous legendary Arabian bird
rom/ a gypsy man
rya/ colourful Scandinavian knotted-pile rug
sal/ a salt
saw/ saying or proverb
say/ delicate woollen fabric
seg/ stud or metal plate in sole of a shoe to prevent wear
sic/ thus
suq/ Middle Eastern marketplace
taj/ crown or head-dress
taw/ to prepare skins by soaking, salting, stretching and paring
ted/ to spread grass for drying
teg/ a sheep in its second year; the fleece of such a sheep
tej/ Ethiopian honey-mead
tex/ unit of measurement of fineness of fibres and yarn
tod/ old unit of weight of wool equal to 28 pounds
tog/ unit of measurement for insulation properties of fabric
ton/ unit of cooling power equal to 12,000 BTU per hour
tot/ bone or other object retrieved from garbage pile
tow/ bundle of untwisted natural fibres
tup/ ram; pile-driver; striking face of steam hammer or jackhammer
tye/ inclined trough for washing ore
ure/ use; custom
vis/ force; power
vug/ small cavity in a rock
wen/ enormously congested city
wey/ old measure for dry goods usually equal to 40 bushels
wis/ to know, to believe
wye/ a Y-branching pipe or railroad track arrangement
wyn/ old English rune having value 'w'
yad/ rod used by readers of the Torah as a pointer for following text
yag/ synthetic diamond made of yttrium aluminum garnet
yam/ posting-house along a road
yaw/ to move unsteadily side to side; to rotate about a vertical axis
yen/ craving or yearning
yeo/ stream or drain used in mining
yew/ to rise, as a layer of froth in a boiling liquid
yex/ to hiccup, belch or spit
yok/ pejorative Jewish term for a non-Jew
yon/ yonder; that over there; those over there
zek/ inmate of prison labour camp
zel/ form of Oriental cymbal
zho/ cross between a yak and a cow
zug/ waterproof leather used for boots
Reference: http://phrontistery.info
