Among other descriptions, Merriam-Websters Collegiate Dictionary defines "WORD"  as a NOUN. Among its definitions we selected: "Any segment of written or printed discourse ordinarily appearing between spaces or between a space and a punctuation mark." 
Intuitively, we may speculate that our Human Ancestors started communicating  with each other by grunting, maybe by hooting, crying or shouting and gradually, these "sounds coming from their mouth" began shaping distinct sounding sounds that what we called words. With time,  words got arranged into  sentences and we have Language, There is no other natural communication system like the human language.
Every  second, in every country of the world,  a  person is using  a vocabularies of  tens of thousands of words to communicate with each other. But, we need to be careful of what words we use, because  Words are powerful.  They can uplift people,  they can hurt people and they can kill.
Religious  leaders: Jesus, Buddha, Muhammad, Martin Luther, Joseph Smith, John Wesley,  among others.  used words to bring people together and the philosophers used them  to spread their thoughts,  there was a also a HITLER, who used his speeches to create hatred for some  people and words that encouraged to kill them.
So we all  need words to communicate with other people but we should be very careful in selecting or words,  because each word we utter has POWER.  Our words could help built up a person's ego or destroy it completely.  Encourage or discourage.  Hurt or heal. Send another human being in the right direction or in the wrong  direction by planting  in their hearts the seed of love, or planting the  seeds of hatred in their minds.  THINK ABOUT IT.