Concise Bible Dictionary:
The name given by Jacob to the heap of stones raised to witness the covenant made between him and Laban. It signifies, as in the margin, “heap of witness” (Gen. 31:47-48).
Potts’ Bible Proper Names:
Heap of witness:― a heap of stones erected as a witness to the covenant between Jacob and Labon, [GILEAD], Gen. 31:47. {Tumulus testimonii}