سجود
Sujūd
Prostration in the ritual prayer, with the forehead on the ground; the singular is sajda.
What it means
Sujūd is the plural of sajda and also the general noun for prostrating. In every unit (rakʿa) of the ritual prayer the worshipper makes two prostrations, placing the forehead, nose, palms, knees and toes on the ground and saying words of glorification. It is the lowest posture of the prayer. The Quran refers to those who bow and prostrate as a mark of the believers (48:29) and commands, “O you who believe, bow and prostrate and worship your Lord” (22:77). Beyond the daily prayer, there are also prostrations for reciting certain verses, called sajdat al-tilāwa, and the prostration of thanks, sajdat al-shukr, which some schools allow.
Often misunderstood as
The posture is often described in English as self-abasement, but it is an act of worship in which the worshipper draws close to God and shows that all honour belongs to Him.
What the sources say
The Prophet Muhammad (peace be upon him) said that the closest a servant is to his Lord is when in prostration, so one should make many supplications in it (Sahih Muslim). The wording most Muslims say in it is subḥāna rabbiya al-aʿlā, “glory to my Lord, the Most High”.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 55, listed as SUJŪD. The definition is restated here.