What is the meaning of the word "articulate"?

Definitions:

expressing yourself easily or characterized by clear expressive language adjective
- articulate speech
to express or state clearly verb
- I articulated my needs.
to provide with a joint verb
- I articulated the bat skeleton.
to put into words or an expression verb
- I'm trying to articulate my feelings here, but I'm having difficulty.
to speak, pronounce, or utter in a certain way verb
- I was known to articulate the letter t very clearly.
to unite by forming a joint or joints verb
- The ankle bone articulates with the leg bones to form the ankle bones.