Lexical Definition

‎ἅπτω‎ háptō (hap'-to) to touch ^G:V
a primary verb

kindle, light.

• properly, to fasten to, i.e. (specially) to set on fire

Abbott-Smith

ἅπτω, [in LXX chiefly for נגע;]
prop., to fasten to; hence, of fire, to kindle, light: Lk 8:16 11:33 15:8, Ac 28:2. Mid., c. gen., to fasten oneself to, cling to, lay hold of (so in π.; MM, s.v.): Mt 8:3, 15, Jo 20:17, al.; of carnal intercourse, I Co 7:1; with reference to levitical and ceremonial prohibitions, II Co 6:17, Col 2:21; of hostile action, I Jo 5:18 (cf. ἀν-, καθ-, περι- άπτω).
SYN.: θιγγάνω, ψηλαφάω. ἅ. is the stronger, θ., to touch, the lighter term. ψ. is to feel, as in search of something (Tr., Syn., § xvii; Lft., Col., 201 f.).

Abbott-Smith References

Liddell-Scott-Jones

ἅπτω,

future ἅψω: aorist ἧψα:—passive, perfect ἧμμαι, Ionic dialect ἅμμαι[Refs 5th c.BC+]: future ἅψομαι[Refs 8th c.BC+] (συν-) [Refs 2nd c.AD+] —middle, see.below (compare ἑάφθη):—fasten or bind to, used by [Refs 8th c.BC+]active, ἅψας ἀμφοτέρωθεν.. ἔντερον οἰός (of a lyre-string) [Refs 8th c.BC+]; once in middle, ἁψαμένη βρόχον.. ἀφ᾽ ὑψηλοῖο μελάθρου having fastened the noose to the beam (to hang herself), [Refs]; so later ἅψεται ἀμφὶ βρόχον.. δείρᾳ[Refs 5th c.BC+]:—active, βρόχους ἅ. κρεμαστούς[Refs 5th c.BC+]

__2 join, ἅ. χορόν[Refs 4th c.BC+]; πάλην τινὶ ἅ. fasten a contest in wrestling on one, engage with one, [Refs]: —passive, ἅπτεσθαι τὴν Μεγαρέων πόλιν καὶ Κορινθίων τοῖς τείχεσιν[Refs 4th c.BC+]
__II more frequently in middle, ἅπτομαι, future ἅψομαι, aorist ἡψάμην[Refs 5th c.BC+], with perfect passive ἧμμαι[Refs 5th c.BC+]:—fasten oneself to, grasp, c.genitive, ἅψασθαι γούνων[Refs 8th c.BC+]; ἅπτεσθαί τινος, Latin manus inicere alicui, [Refs 5th c.BC+]; τῶν σφυγμῶν feel the pulse, [Refs 2nd c.AD+]: metaphorically, take hold of, cleave to, [Refs 5th c.BC+]
__II.b absolutely, τῶν μὲν γὰρ πάντων βέλε᾽ ἅπτεται for the spears of all the Trojans reach their mark, [Refs 8th c.BC+]
__II.c ἅ. τῆς γῆς land, [Refs 1st c.BC+]
__III metaphorically, engage in, undertake, βουλευμάτων[Refs 5th c.BC+]; πολέμου prosecute it vigorously, [Refs 5th c.BC+]; ἐπιτηδεύματος[Refs 5th c.BC+] attack, impugn the argument of another, [Refs]; τούτων ἥψατο touched on these points, handled them, [Refs 5th c.BC+]; but also, touch on, treat superficially, [Refs 5th c.BC+]
__III.b absolutely, begin, set to work, ταῖς διανοίαις[Refs 5th c.BC+]
__III.2 fasten upon, attack, [Refs 5th c.BC+]; of diseases, ἧπταί μου[Refs 5th c.BC+]; ὅσα ἅπτεται ἀνθρώπων all that feed on human flesh, [Refs]
__III.2.b lay hands on, χρημάτων[Refs 5th c.BC+]
__III.3 touch, affect, ἄλγος οὐδὲν ἅπτεται νεκροῦ[Refs 5th c.BC+]; make an impression upon, ἡμῶν[Refs 2nd c.BC+]
__III.4 grasp with the senses, perceive, [Refs 5th c.BC+]; apprehend, τῆς αἰτίας[Refs 4th c.BC+]
__III.5 have intercourse with a woman, [NT+5th c.BC+]
__III.6 come up to, reach, overtake, [Refs 5th c.BC+]; attain, τῆς ἀληθείας[Refs 5th c.BC+]; but also with genitive, Ἡρακλέος σταλᾶν[Refs]
__III.7 make use of, avail oneself of, τῆς τύχης[Refs 5th c.BC+]
__III.8 Geometry texts, of bodies and surfaces, to be in contact, [Refs 4th c.BC+]; of lines or curves, meet, [Refs 3rd c.BC+]; touch, [Refs 3rd c.BC+]; pass through a point, [Refs 3rd c.BC+]; of points, lie on a line or curve,[Refs]; ἅπτεται τὸ σημεῖον θέσει δεδομένης εὐθείας the locus of the point is a given straight line, [Refs 3rd c.AD+]
__B active, kindle, set on fire (i.e. by contact of fire), [Refs 5th c.BC+] (so in middle, [Refs 5th c.BC+]:—passive, to be set on fire, ὁ μοχλὸς ἐλάϊνος ἐν πυρὶ μέλλεν ἅψεσθαι[Refs 8th c.BC+]; ὡς ἅφθη τάχιστα τὸ λήιον.. ἅψατο νηοῦ as soon as the corn caught fire, it set fire to the temple, [Refs 5th c.BC+]; πυρῆς ἤδη ἁμμένης[Refs 5th c.BC+]
__B.II ἅ. πῦρ kindle a fire, [Refs]:—passive, ἄνθρακες ἡμμένοι red-hot embers, [Refs 5th c.BC+]
__B.III cook, [Refs 2nd c.AD+]

_{LSJ Scripture Refs: 1Cor.7.1}