Definition of precaution:
(n) :
previous caution or care; caution previously employed to prevent mischief or secure good; as, his life was saved by precaution; a measure taken beforehand to ward off evil or secure good or success; a precautionary act; as, to take precautions against accident
"the
ancient philosophers treasured up their supposed discoveries with miserable precaution. --J. H. Newman."
(v) :
to warn or caution beforehand. --Locke; to take precaution against. [R.] --Dryden