shirk: to associate others with Allah in those things which are specific to Him. This can occur in (1) belief, e.g. to believe that other than Allah has the power to benefit or harm, (2) speech, e.g. to swear by other than Allah and (3) action, e.g. to bow or prostrate to other than Allah.
اللّهُـمَّ إِنّـي أَعـوذُبِكَ أَنْ أُشْـرِكَ بِكَ وَأَنا أَعْـلَمْ، وَأَسْتَـغْفِرُكَ لِما لا أَعْـلَم.
Allahumma innee aAAoothu bika an oshrika bika wa-ana aAAlam, wa-astaghfiruka lima la aAAlam.
‘O Allah, I take refuge in You lest I should commit shirk with You knowingly and I seek Your forgiveness for what I do unknowingly.’