Integration

yogash- to join, to integrate
chitta- the screen of mind that consciousness observes
vritti- fluctuations, changes, modifications
nirodhah- mastery, control, regulation, channeling

My Translation:
Yoga is learning to keep your mind focused without effort.

Chitta is the screen on which our world plays.  We do not see the world as directly as we think.  What we see is a combination of sensory input and memory.  Our senses do not give us complete information, but our minds fill in the missing gaps from memory.  All too often though, the screen is disturbed by memories that are not necessarily relevant to the reality we are attempting to perceive.  By a threefold process of letting go, observing without attachment, and finally inspecting these memories when they present themselves, one can gradually weaken their control over the mind.  When this is done with sincere effort, but without straining, peace of mind can be achieved.

atha- now, which implies that something has come before
yoga- to join, to integrate
anu- within, traditionally
shasanam- to explain, discipline

My Translation:
And now we will discuss yoga