Boyd’s Bible Dictionary:
Fatted calf a luxury (Gen. 18:7; 1 Sam. 28:24; Amos 6:4; Luke 15:23). Molten calf (Ex. 32:4; 1 Kings 12:28), gilded structures. Calf worship denounced (Hos. 8; 10; 13:2). “Calves of our lips” (Hos. 14:2), fruits of our lips.
Concise Bible Dictionary:
The young of cattle whether male or female. A calf was offered for a sin-offering for Aaron, and a calf and a lamb for a burnt-offering for the people, at the commencement of Aaron’s service (Lev. 9:2, 8).
A calf was kept by the affluent, ready for any special meal, such as was presented tender and good to the angels by Abraham (Gen. 18:7); which is also described as “the fatted calf” in the parable of the Prodigal Son (Luke 15:23). The calf or ox is used typically to represent one of the attributes of God in governmental power, namely, firm endurance (Rev. 4:7; compare Ezek. 1:10).