A winged insect with four legs (from the scientific family Orthptera). These insects are related to grasshoppers and locusts. Israelites considered crickets ceremonially clean to eat (Leviticus 11:22). The reference in the Bible may actually be describing one of the growth stages of the locust, rather than what we call crickets today.
Cricket
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.