ichidan verb
clench (teeth); engage (gears)
Used for bringing two things into tight contact: teeth, gears, or mechanical parts. Often implies a firm, interlocking fit.
痛みに耐えて歯を噛み合わせた。
He clenched his teeth against the pain.
ギアを噛み合わせ
Engage the gears and then release the clutch.
ichidan verb
set to fighting; pit against each other
Figurative use: to make two people or animals fight, often by provoking them. Less common than the literal sense.
彼は二人を噛み合わせて喧嘩させた。
He set the two against each other and made them fight.