Two Hundred Questions and Answers
In The Name of Allaah, The Most Merciful, The Bestower of Mercy
What is the meaning of worship?
الْعِبَادَةُ إسْمٌ جَامِعٌ لِكُلِّ مَا يُحِبُّهُ اللَّهُ وَيَرْضاهُ مِنَ الْأَقْوَالِ والْأَعْمَالِ الظَّاهِرَةِ وَالْبَاطِنَة
”Worship is a comprehensive term including everything that Allaah loves and is pleased with of statements and actions, apparent and unapparent. 
Shaikh Saaleh Al-Fawzaan (hafidha-hullaah) said:
Everything Allaah loves and is pleased with of the apparent actions of the limbs and the unapparent actions of the heart are regarded as worship. And whatever Allaah is displeased with cannot be regarded as worship, even if a person wishes to draw close to Allaah with it. Therefore that which Allaah is not pleased with cannot be regarded as worship, even if the person who (performs such actions) intends good by way of it. Innovations in Religion, superstition and the affairs of shirk are not acts of righteousness in the sight of Allaah because Allaah is neither pleased with them nor did He permit them. So worship is a comprehensive term including everything that Allaah loves and Allaah neither loves disbelief, shirk innovation and newly invented matters in religion, nor is He pleased with all of that. Allaah loves that what He has legislated is acted upon and this is what worship is. 
[200 Su’aal Wa Jawaab Fil-Aqeedah Al-Islaamiyyah: page:14]