“BACKCHAT” is a valid word. — 21 points Scrabble

catcha drawback or difficulty that is not readily evident
batchall the loaves of bread baked at the same time
abackhaving the wind against the forward side of the sails
thack
baccaan indehiscent fruit derived from a single ovary having one or many seeds within a fleshy wall or pericarp: e.g. grape; tomato; cranberry

backthe posterior part of a human (or animal) body from the neck to the end of the spine
batha vessel containing liquid in which something is immersed (as to process it or to maintain it at a constant temperature or to lubricate it)
chatan informal conversation
hackone who works hard at boring tasks
bachGerman baroque organist and contrapuntist; composed mostly keyboard music; one of the greatest creators of western music (1685-1750)
tackthe heading or position of a vessel relative to the trim of its sails
bahtthe basic unit of money in Thailand
takathe basic unit of money in Bangladesh; equal to 100 paisa
kata
caca
tachmeasuring instrument for indicating speed of rotation
khatthe leaves of the shrub Catha edulis which are chewed like tobacco or used to make tea; has the effect of a euphoric stimulant
acta

acta legal document codifying the result of deliberations of a committee or society or legislative body
catfeline mammal usually having thick soft fur and no ability to roar: domestic cats; wildcats
aahexpress admiration and pleasure by uttering `ooh' or `aah'
hatheaddress that protects the head from bad weather; has shaped crown and usually a brim
caba compartment at the front of a motor vehicle or locomotive where driver sits
batnocturnal mouselike mammal with forelimbs modified to form membranous wings and anatomical adaptations for echolocation by which they navigate
aha
katthe leaves of the shrub Catha edulis which are chewed like tobacco or used to make tea; has the effect of a euphoric stimulant
tabthe bill in a restaurant
bah
baathe cry made by sheep
abaa loose sleeveless outer garment made from aba cloth; worn by Arabs
kab

ata highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium
ah
ha(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day
taa hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
baa soft silvery metallic element of the alkali earth group; found in barite
kaunknown god; an epithet of Prajapati and Brahma
aaa dry form of lava resembling clinkers
aba bachelor's degree in arts and sciences

BACKCHAT