Define what defines ?

Teaching kids the definition of words is easy we just pull out dictionary/ google and wah lah poof the answer appears.Have you ever questioned who, what, when like who decided how the words would be used and in what context. : Pail,Bucket,Tub: Some people will say Im going to fetch a pail of water,I need to get a bucket for leak in roof,I need big tub for ice.These items are similar yet people use their context to which ever one best suites them.Love,Lust Infatuation:Some people want to be in love, need to be in love, this feeling of a perfect ever after fantasy land,Some people crave lust the passion of a lover that urge in pit of your stomach that keeps you aching all night for their touch,Some people aquire both the innonence and secure feeling of love, the overwhelming desire...Define what defines these to you.