In this verse, I've heard it translated both as 'made the earth a wide expense' and 'made the earth egg-shaped'. Could an arab speaker please explain whether dahaahaa actually means egg?
In his book, The Qur'ân and the Orientalists, Dr. Muhammad Mohar Ali, former Professor of the History of Islam at the Islamic University of Madinah and Al-Imâm University in Riyadh, provides an extensive and detailed discussion on the Qur'anic view of the earth. Here is a relevant excerpt:
Now, the very first expression in the series, dahâhâ, is noticeably distinctive and different in genre from the rest. Watt, following many other previous translators, renders it as "spread out". But the exact and correct meaning of the term, keeping in view its root, rather provides a very positive Qur'anic evidence in support of the spherical shape of the earth. For dahâ means to "shape like an egg", its noun being dahiyah, which the Arabs still use to mean an egg. Nevertheless, even if we do take the interpretation of 'spread out' as many other commentators and translators do, there is still no conflict with science because, as Syed Qutb points out, the idea that the earth's crust was spread out after the formation of the atmosphere (which could refer either to continental drift or actual cooling of the crust) is a fact confirmed by modern scientific study. Please see this related article:
 M. FATHÎ 'UTHMAN, "Al-'ard Fî al-Qur'ân al-Karâm", Proceedings of the First Islamic Geographical Conference", Riyadh, 1404/1984, Vol. IV, 127; A. M. SOLIMAN, Scientific Trends in teh Qur'ân, London (Ta-Ha Publications), 1985, p. 16. (M. Mohar Ali, The Qur'ân and the Orientalists, Jam'iyat 'Ihyaa' Minhaaj Al-Sunnah 2004, p.75)
earth with bulge