Definition (full): to strike, to knock together, surround, circulate
Strong's Exhaustive Concordance
A primitive root; to strike with more or less violence (beat, fell, corrode); by implication (of attack) to knock together, i.e. Surround or circulate -- compass (about, -ing), cut down, destroy, go round (about), inclose, round.
KJV: And under the brim of it round about there were knops compassing it, ten in a cubit, compassing the sea round about: the knops were cast in two rows, when it was cast.
NASB: Under its brim gourds went around encircling it ten to a cubit, completely surrounding the sea; the gourds were in two rows, cast with the rest.