STEP Hebrew Lexicon: נָצַר

1) to guard, watch, watch over, keep

1a) (Qal)

1a1) to watch, guard, keep

1a2) to preserve, guard from dangers

1a3) to keep, observe, guard with fidelity

1a4) to guard, keep secret

1a5) to be kept close, be blockaded

1a6) watchman (participle)