There are six Hebrew words translated as “oak.”
'El occurs only in the word El-paran (Genesis 14:6). The Septuagint renders by “terebinth.” In the plural form this word occurs in Isaiah 1:29; 57:5 (King James Version marginal note and Revised King James Version, “among the oaks”); 61:3 (“trees”). The word properly means strongly, mighty, and hence a strong tree.
'Elah, Genesis 35:4, “under the oak which was by Shechem” (Revised King James Version marginal note, “terebinth”). Isaiah 6:13, King James Version, “teil-tree;” Revised King James Version, “terebinth.” Isaiah 1:30, Revised King James Version marginal note, “terebinth.” Absalom in his flight was caught in the branches of a “great oak” (2 Samuel 18:9; Revised King James Version marginal note, “terebinth”).
'Allon, always rendered “oak.” Probably the evergreen oak (called also ilex and holm oak) is intended. The oak woods of Bashan are frequently alluded to (Isaiah 2:13; Ezek. 27:6). Three species of oaks are found in Israel, of which the “prickly evergreen oak” (Quercus coccifera) is the most abundant. “It covers the rocky hills of Palestine [Israel] with a dense brushwood of trees from 8 to 12 feet high, branching from the base, thickly covered with small evergreen rigid leaves, and bearing acorns copiously.” The so-called Abraham's oak at Hebron is of this species. Tristram says that this oak near Hebron…
“has for several centuries taken the place of the once renowned terebinth which marked the site of Mamre on the other side of the city. The terebinth existed at Mamre in the time of Vespasian, and under it the captive Jews were sold as slaves. It disappeared about A.D. 330, and no tree now marks the grove of Mamre. The present oak is the noblest tree in Southern Palestine [Israel], being 23 feet in girth, and the diameter of the foliage, which is unsymmetrical, being about 90 feet.” —Henry Baker Tristram, The Natural History of the Bible