I might be able to help with some, our Sigung used a very old fashioned dialect of Cantonese, so I may be wrong… Please don’t take my post as absolute. When Chinese is Romanized, much is lost in the translation, and spelling is widely varied. 
fahn jong choy - ‘fahn’ usually means to reverse or inverted ( as in ‘fahn gok choy’ - inverted hook punch), jong choy is ‘crashing fist’. I personally have seen or heard of ‘fahn jong choy’, but I would guess ‘inverted crashing fist’
pow choy - my understanding is it means ‘canon fist’ or straight (long) armed uppercut
chin gee choy- not sure, sorry
biu jong- ‘biu’ means ‘to dart’ or ‘spear’ i think. a shorter version of jong choy
been choy - our version of CLF ( Green Cloud) spells it ‘biin’, but it essentially means ‘whipping fist’
lao jerng - not sure
yum jerng - i believe it’s a palm to groin. ‘liu yum teui’ is groin aggitating kick in our version
biu jee- again, ‘biu’ is ‘darting’ or ‘spearing’, jee ( we spell it ‘jih’) is finger
dahn na- not sure, ‘na’ means ‘lock’ or ’ control’ ( ‘chin na’ or ‘kahm na’)
kong jerng - not sure about ‘kong’, jerng ( or ‘jueng’) usually means ‘palm’
cham kiu- ‘sinking bridge arms’, ‘cham’ means ‘to sink’, ‘kiu’ is ‘bridge arm’
poon kiu - ’ clinging bridge arm’ , ‘poon sau’ ( which we call it) is ‘clinging block’
chang fu girk- not sure. ‘fu’ means ‘tiger’
oi buy leen toi- well, ‘bai liin teui’ is outside crescent kick. otherwise i’m not sure
king nai - not sure
Hope some of this helps
-david