Wa alaikum assalam,
The meaning of 'sujud' varies in Arabic according to context and doesn't always mean a physical human prostration. In the context of Iblis or the angels this does not mean a 'physical' prostrations like human's perform to God.
SJD means to become submissive, humble, to make obeisance, lowly, to pay respect, or to even bend down (bowing) and prostrate. This root word forms other words such as 'Masjid' which is a place where 'SJD' takes place.
For example, it would be inappropriate in light of the Quran's context to understand Prophet Joseph's (pbuh) family, including his father (also a prophet), to have prostrated physically to the ground to Prophet Joseph (12:100). Similarly, in Prophet Joseph's dream where he saw a vision of the stars / planets, sun and the moon prostrate to him (12:4), one would least be expected to understand this to be a physical prostration.
There are numerous other examples from the Quran.
In the context of prayer and God, it means a physical prostration by means of bending oneself towards the ground in complete subservience. However, when the word is used in relation to entities other than God, different shades of meaning are admitted.
I hope my article below helps, God willing.
WHAT IS THE QURANIC SUJUD (PROSTRATION)?http://www.facebook.com/l/zAQHzSHGRAQEyRDvG8f8c9Ri7jag4niaPY_5fameWfxc3yw/quransmessage.com/articles/sujud%2520FM3.htmRegards,
Joseph.