Boyd’s Bible Dictionary:
(knob). Ornamental knobs, or reliefs (Ex. 25:31-36; 1 Kings 6:18).
Concise Bible Dictionary:
Ornaments adopted in the construction of the golden candlestick and in the temple of Solomon.
1. kaphtor, “a crown or circlet” (Ex. 25:31-36; Ex. 37:17-22).
2. peqaim, “wild cucumbers,” egg shaped (1 Kings 6:18; 1 Kings 7:24). The definite form of these ornaments is not known, save as may be surmised from the relievo on the Arch of Titus at Rome.