Relation between crush and krushiti [closed]
Solution 1:
According to the Online Etymological Dictionary, the ultimate etymology of crash beyond Old French cruissir, ‘gnash (teeth), crash, smash, break’ is not certain, but may well be from an originally Germanic root from the Frankish superstrate, *krostjan, cognate to Goth 𐌺𐍂𐌹𐌿𐍃𐍄𐌰𐌽 (kriustan), ‘to gnash, break in pieces’, OSwed krysta, ‘to gnash, crackle’.
Starting from the end, the ʃ (š) in common with your Slavonic word is not original even in French, but sometimes occurs when an original French s is borrowed into English. Compare push, OF poulser (ModF pousser), from Lat pulsare, ‘to beat, strike, push’; brush, OF broisse, broce; quash, OF quasser, casser ‘to annul, declare void’ and/or Late Lat quassare, cassare, from cassus, ‘null, void, empty’.
If the connection to Gothic and Old Swedish is correct, then the reconstructed Proto-Germanic root is *krus-, *kriustan-, *krusta-z, which in turn derives from a PIE root *graus-, *grauks-.
Only in the Germanic descendents of this root does the initial consonant devoice: in Slavic languages the root is reconstructed as *grūxātī, *grūšītī, *grūšā and in Baltic as the verbal root *grukš-ē̂-, more distantly Lat ingruo, ‘attack, assail’.
In a Slavic word, then, one would expect the voiced consonant to be retained. Without initial and final consonant, there isn’t much left to suggest that крушити and crash are even distant cognates.
This does, however, suggest грохнуться (grokhnut'sya), ‘fall, crash’ as a distant cousin of crash by way of a common PIE root, but not Old Slavonic крушити (krushiti).
Solution 2:
Your linked page gives:
krushít' noun. krushíti, verb. -Slavic.
Incompletative "-kroushiti"
from the Greek, συντρίβειν, θραύειν, κρούειν, [to crush]. i.e., syntrívein, thrávein, kroúein,
[Compare] krúshiti «kroshit'», Slovenian. krúšiti, Czech. krušiti, Polish. kruszyć, Byeloruss. krušić.
Reference: krukh, krokhá; See Berneker 1, 628 i sl.; Meyye, MSL 14, 363.
For "crush" the OED, the entry for which was last updated in 1893, gives
Etymology: apparently < Old French croissir, croisir, sometimes cruis(s)ir, rarely crusir, croussir, to gnash (the teeth), to make a crashing or cracking noise, to crash, crack, smash, break; in Cotgrave, 1611, ‘to cracke, or crash, or crackle, as wood thats readie to breake’; = Catalan croxir, Spanish cruxir, crujir to crackle, to rustle, Italian †croscere, crosciare to crackle, crash, clatter; ‘also to squease, to crush, or squash’ (Florio); medieval Latin cruscire to crackle (Du Cange). The Romanic word is apparently of German origin: see Diez and Mackel, and compare Middle High German krosen, krösen to gnash with the teeth, make a crackling noise, bruise or crush with a crackling sound, crash, craunch, for which Hildebrand infers an Old High German chrosôn, chrosian.
The notion of noise present in the foreign words appears also in early uses of cruss , crussh , but is practically absent from later use, being now expressed by crash v.
Although the Greek κρούειν, [to crush]. i.e., kroúein, is not mentioned, I think that there is probably a good chance that the two words are related.