collapse vs slide down

collapse is a noun but slide down is not a noun.

Word	Noun	Adjective	Verb	Adverb
collapse	Yes	No	Yes	No
slide down	No	No	Yes	No

As verbs, slide down is a hyponym of collapse; that is, slide down is a word with a more specific, narrower meaning than collapse:

Other hyponyms of collapse include go off, implode, buckle, crumple, flop, break, sink, slump.

collapse (noun)	slide down (noun)
the act of throwing yourself down; collapse; sink
a natural event caused by something suddenly falling down or caving in
a sudden large decline of business or the prices of stocks (especially one that causes additional failures)
an abrupt failure of function or complete physical exhaustion

collapse (verb)	slide down (verb)
collapse due to fatigue, an illness, or a sudden attack	fall or sink heavily
lose significance, effectiveness, or value
suffer a nervous breakdown
break down, literally or metaphorically
fold or close up
fall apart
cause to burst