I have never run across all those words. They seem not only close in sound but be used in similar situations (according to my research), that I sometimes become unable to choose which one to use.
The Merriam-Webster says (excerpt):
to make a clash <cymbals clashed>
to come into conflict <where ignorant armies clash by night — Matthew Arnold>; also : to be incompatible <the colors clashed>
: to cause to clash
- a: to break violently and noisily : SMASH
- b: to damage (an airplane) in landing
- a: to cause to make a loud noise <crash the cymbals together>
- b: to force (as one's way) through with loud crashing noises
4: to move toward aggressively (as in fighting for a rebound) <basketball players crashing the boards>
5: to cause (a computer system, component, or program) to crash
- a: to break or go to pieces with or as if with violence and noise
- b: to fall, land, or hit with destructive force
- c: to decline suddenly and steeply
- d of a computer system, component, or program : to suffer a sudden major failure usually with attendant loss of data
to make a smashing noise <thunder crashing overhead>
to move or force one's way with or as if with a crash <crashes into the room>
- a: to squeeze or force by pressure so as to alter or destroy structure <crush grapes>
- b: to squeeze together into a mass
3: to reduce to particles by pounding or grinding <crush rock>
- a: to suppress or overwhelm as if by pressure or weight
- b: to oppress or burden grievously <crushed by debt>
- c: to subdue completely
to become crushed
to advance with or as if with crushing
From above, many questions arise. For example:
- clash(intr.) 1 and crash(tr.) 2a (= crash(intr.) 2?) shares similar examples but does it mean they're synonymous in this way?
- Definitions in crash use "break" while crush use "squeeze", and does it mean crush is a subtype of crash, or the two are separate in manner of using forces?
- Is, perhaps, the choice of crash and crush predictable from the object? Which is more correct to say "His dream was crashed." and "His dream was crushed."?
Ultimately, if possible, I want to know whether, for native speakers, these words indeed share some kind of base sense but differ due to external factors, or are essentially different but have many common usages. If the latter, what's the crucial difference between them?