small cord, rope

Strong’s Dictionary of Greek Words:

Greek:
σχοινίον
Transliteration:
schoinion
Phonic:
skhoy-nee’-on
Meaning:
diminutive of σχοῖνος (a rush or flag-plant; of uncertain derivation); a rushlet, i.e. grass-withe or tie (generally)
KJV Usage:
small cord, rope

From Manners and Customs of the Bible:

Job 41:22Canst thou put an hook into his nose? or bore his jaw through with a thorn? (Job 41:2). Canst thou put a hook into his nose? or bore his jaw through with a thorn?
1. Agmon, “hook,” is more correctly a rush-cord or rope made of reeds, (Gesenius;) and the question of the text suggests the wonderful strength of the leviathan by the impossibility of putting a rope around his nose, thus binding his jaws.
2. Choach, “thorn,” is really a ring; and the text probably refers to a custom, very ancient and still practiced, of inserting a strong iron ring into the jaw of a fish as soon as caught. A cord is fastened to the ring and the fish is let down into the water, where it remains until the fisherman has an opportunity of selling it.