Strong’s Lexicon
Definition - To keep, to guard, to observe, to watch over
Word Origin - From a primary word (teros, meaning “a guard”)
Usage - The Greek verb “τηρέω” (téreó) primarily means to keep or guard something with care. It conveys the idea of watching over something attentively, maintaining it in its original state, or observing it with the intent to preserve. In the New Testament, it is often used in the context of keeping commandments, guarding the faith, or observing teachings.
HELPS Word-studies
5083 tēréō (from tēros, “a guard”) – properly, maintain (preserve); (figuratively) spiritually guard (watch), keep intact.
Strong’s Exhaustive Concordance
hold fast, keep
From teros (a watch; perhaps akin to theoreo); to guard (from loss or injury, properly, by keeping the eye upon; and thus differing from phulasso, which is properly to prevent escaping; and from koustodia, which implies a fortress or full military lines of apparatus), i.e. To note (a prophecy; figuratively, to fulfil a command); by implication, to detain (in custody; figuratively, to maintain); by extension, to withhold (for personal ends; figuratively, to keep unmarried); by extension, to withhold (for personal ends; figuratively, to keep unmarried) — hold fast, keep(er), (pre-, re-)serve, watch.