Quick Definition
συντηρέω v. I preserve, keep safe, keep in mind
Strong's Definition
to keep closely together, i.e. (by implication) to conserve (from ruin); mentally, to remember (and obey)
Derivation: from G4862 (σύν) and G5083 (τηρέω);
KJV Usage: keep, observe, preserve
UBS Dictionary of the Greek New Testament
verb | τηρέω
13.33 · Be, Become, Exist, Happen · State
to keep together, to preserve both to cause something to continue along with something else
29.1 · Memory and Recall · Storing of Information
to cause oneself to be fully aware of, to keep in mind, to remember to exert mental effort in storing information so as to have continual access and use of it An equivalent of ‘to keep in mind’ may be ‘to keep thinking about’ or ‘to continue to think about’ or even ‘not to stop thinking about.’
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
συν-τηρέω, -@: impf. 3 pers. sing. wuvernper; pres. pass. 3 pers. plur. συντηροῦνται; [fr. Aristot. de plant. 1, 1 p. 816%, 8 down] ; a. lo preserve (athing from perishing or being lost) : τί, pass. (opp. ἰο ἀπόλλυσθαι), Mt. ix. 17; Lk. v. 38 [fT WH om. Tr br. the el.]; τινά, to guard one, keep him safe, fr. a plot, Mk. vi. 20 (ἑαυτὸν ἀναμάρτητον, 2 Mace. xii. 42 [ef. Tob. i. 11; Sir. xiii. 12]). b. to keep within one’s self, keep in mind (a thing, lest it be forgotten [ef. σύν, II. 47) : πάντα τὰ ῥήματα, Lk. ii. 19 (τὸ ῥῆμα ἐν τῇ καρδίᾳ μου, Dan. vii. 28 Theod.; τὴν γνώμην παρ᾽ ἑαυτῷ, Polyb. 31, 6, 5; [absol. Sir. xxxix. 2]).
Mounce Concise Greek Dictionary
συντηρέω syntēreō 3x
to keep safe and sound, Mt. 9:17; to observe strictly, or, to secure from harm, protect, Mk. 6:20; to preserve in memory, keep carefully in mind, Lk. 2:19*
Abbott-Smith Greek Lexicon
συν-τηρέω, -ῶ
[in LXX: Ez 18:19 (שׁמר), Da TH 7:28 A (נְטַר), Si 13:12 and freq., To 1:11, II Mac 12:42, al. ;]
"perfective" of τηρέω (v. M, Pr., 113, 116),
to preserve, keep safe, keep close: c. acc. pers., Mk 6:20; c. acc. rei, Mt 9:17; ἐν τ. καρδίᾳ, Lk 2:19 (Arist. and later writers; cf. MM, xxiv).†
Moulton & Milligan — Vocabulary of the Greek NT
συντηρέω. For this perfective of τηρέω (Proleg. pp. 113, 116) = ‘‘keep safe” (1) c. acc. pers., as in Mk 67°, cf. P Tebt 11. 4164 (iii/A.D.) πᾶν ποίησον συντηρῆσαι τὴν γυναῖκά μου ἕως παραγένομε (. παραγένωμαι), ‘do everything possible to protect my wife until I arrive” (Edd.), P Oxy XII. 1418 (A.D. 247) σ]υντηρῆσαι τὸν παῖδα, and the iv/A.D. Gnostic charm 724. VI. 9241 ἢ phy φυχάξῃς Kal συντηρήσῃς Apias ἀπὸ τοῦ ἐπιημερινοῦ φρικός, ‘‘ verily guard and protect Aria from ague by day”: and (2) c. acc. rei, as in Mt οἵ, cf. P Bouriant r1o!* (B.c. 88) καλῶς ποιήσεις συντηρῶν τὸν τόπον, BGU IV. 1074* (A.D. 275) τὰ δὲ [ὑἹπὸ το[ῦ] δίὲ τ]οῦ Σεβαστοῦ δ[εδ)]ομένα ὑμῖν νόμιμα καὶ φιλάνθ[ρ]ωπα συντηρῶ, “1 keep safe the laws and privileges granted to you by Augustus,” and Sy// 930 (= 705) (B.C. 112) συντηρῆσαι τὰ ἐκ παλαιῶν χρόνων δεδομένα τίμια καὶ φιλάνθρωπα : see also 2ὁ. 655 (= ὃ 820)" (A.D. 83) μυστήρια ἀπὸ πλείστων ἐτῶν συντετηρημένα. In P Tebt II. 2827 (late ii/B.c.) a guard declares that he will keep the best watch possible over other people’s holdings—gv(Aakiy) ἀλ[λο]τρ[ (ὧν κλή(ρων) συντηιρήσιν ἀπὸ τ[ο]ῦ βελτίζσντου, and in BGU I. τϑο}8 (ii/iii a.p.) a veteran claims that in view of his long military service, exemption from public burdens ought to be ‘‘strictly observed’’ in his case—ém ἐμοῦ συντηρεῖσθαι ὀφείλι. Cf. also 20. IV. 1106! (B.C. 13) & Te ἐὰν λάβῃ ἢ πιστευθῇ σῶα συντηρήσιν (-- εἰν), and 7d. 112618 (Β.6. 8), and for the subst. συντηρεία (not in LS§) cf. Sy// 932 (= %880)5? (A.D. 202) συν[τηρ]είας βουγαρίων.
Liddell-Scott-Jones — Greek-English Lexicon
συντηρέω (suntēreō) — to preserve. συντηρ-έω, keep or preserve closely, ἑαυτὸν ἀδωροδόκητον[LXX]; σ. [τὴν γνώμην] παρ᾽ ἑαυτῇ keep it close, [NT+2nd c.BC+]
2. preserve, maintain, of grants or privileges, [Refs 2nd c.BC+]:—passive, [Refs]; ἀμφότεροι -οῦνται (i.e. ὅ τε οἶνος καὶ οἱ ἀσκοί) [NT]
3. observe strictly, τὸ τῆς φύσεως τέλος [Refs 4th c.BC+]; τὰ νόμιμα[LXX+3rd c.BC+]; τήν τε φιλίαν καὶ τὴν συμμαχίαν [Refs 2nd c.BC+]; σ. τὸ διάστημα keep distance, [Refs 1st c.BC+]
4. watch one's opportunity, συντηροῦντα παίειν [Refs 1st c.AD+]
5. watch over, protect, τοῖς φυλακίταις (i.e. συντάξαι) συντηρῆσαι τὰ.. γενήματα [Refs 1st c.BC+]