What are UNIX commands and directory names?

I summarized it. I will post it as a wiki.
Please feel free to add and edit

• command

ls=list
mv=move
cd=change directory
cp=copy
rm=remove
mkdir=make directory
rmdir=remove directory
chown=changeowner
chmod=change mode
cat=catenate||concatenate
grep="g/RE/p"||global search a regular expression and print
ping=Packet InterNet Groper
sh=shell
bash=Bourne Again Shell
su=Super User||Switch User||Substite User
sudo=superuser do
vi=visual
sed=Stream Editor
unique=unique
awk=Aho, Weinberger, Kernighan #3 Author Names
man=manual
pwd=print working directory
bg=background
fg=foreground
ps=process status
du=disk usage
df=disk free
dd=Dump Data/Data Definition
passwd=password
tar=Tape Archive
wall=Write to ALL users
xargs=eXecute ARGmentS#Source Required
uname=UNIX Name

• directory

/bin=binary
/sbin=System Binary
/usr=User Services and Routines#Not short for User
/var=variable
/lib=library
/tmp=temporary
/dev=device
/etc=Et Cetra
/proc=process
/sys=system
/ucb=University of California at Berkeley

• Other

tty=TeleTYpe
stdin=Standard In
SQL=Structured English Query Language
rc=Run Command#.bashrc

Source
Linux commands become much more familiar when you understand the meaning of words
New UNIX Originating/Reading Dictionary
UNIX Terminology Origin/Reading Dictionary version 1.6 (Feb131995)