"a bridle," is used in James 3:3 (AV, "bits"), and Revelation 14:20 . "The primitive bridle was simply a loop on the halter-cord passed round the lower jaw of the horse. Hence in Psalm 32:9 the meaning is bridle and halter" (Hastings, Bib. Dic.).
from chalinos and ago, "to lead," signifies "to lead by a bridle, to bridle, to hold in check, restrain;" it is used metaphorically of the tongue and of the body in James 1:26; 3:2 .