Lexical Definition

‎λάσχω‎ láschō (las'-kho) to burst ^G:V
a strengthened form of a primary verb, which only occurs in this and another prolonged form as alternate in certain tenses

burst asunder.

• to crack open (from a fall)

Abbott-Smith

* λάσκω,
1. (in cl., poët.) to clang, crash, crack; in late prose, to crack or burst noisily: Ac 1:18 (ἐλάκησεν, perh., however, from λακέω, q.v.; Bl., in l.).
2. (in cl., prose) to scream, shout.†

Abbott-Smith References

Liddell-Scott-Jones

λάσχω,

imperfect ἔλασκον [Refs 5th c.BC+]: future λᾰκήσομαι [Refs 5th c.BC+]aorist 1 ἐλάκησα [ᾰ[Refs]aorist 2 ἔλᾰκον, Epic dialect λάκον [Refs 8th c.BC+]: aorist 1 ἔληξα [Refs 3rd c.BC+]: perfect λέληκα [Refs 8th c.BC+]; participle feminine λελᾰκυῖα [Refs 8th c.BC+] —middle, see below [Refs]:—ring, rattle, crash:

__I of things, ring when struck, λάκε χαλκὸς νυσσομένων ξίφεσίν τε καὶ ἔγχεσι [Refs 8th c.BC+]; also λάκε δ᾽ ὀστέα the bones cracked, broke with a crash, [Refs]; λάκε δ᾽ ἀμφὶ πυρὶ ὕλη crackled, [Refs 8th c.BC+]; ἔλακον ἀξόνων βριθομένων χνόαι creaked under the weight, [Refs 4th c.BC+] —this sense occurs only in aorist 2 active
__II of animals, scream, of the falcon, ὀξὺ λεληκώς [Refs 8th c.BC+]; of the nightingale in the falcon's talons, τί λέληκα; [Refs 8th c.BC+]; also, of dogs, howl, bay, Σκύλλη.. δεινὸν λελακυῖα Od.[same place]; rare in Prose, οὐ μινυρίζει οὐδὲ λέληκεν, of the black eagle, Arist.[same place]:—this sense occurs only in perfect, except in Epic dialect aorist middle, κύνες λελάκοντο [Refs]
__III of human beings, shout, scream, cry aloud, λέληκεν ἢν καὶ μηδέν᾽ ἀνθρώπων ὁρᾷ [Refs 7th c.BC+]; τί λέλακα; [Refs 5th c.BC+]: hence of Oracles, utter, [Refs 5th c.BC+]; also, sing, πρὸς αὐλόν [Refs 5th c.BC+]
__III.2 with accusative cognate, shriek forth, utter aloud, ὀλολυγμόν [Refs 4th c.BC+]; στονόεν λέλακε χώρα [Refs 5th c.BC+]