slow up vs slow

slow up is not an adjective while slow is an adjective.

Word	Noun	Adjective	Verb	Adverb
slow up	No	No	Yes	No
slow	No	Yes	Yes	Yes

As verbs, slow up and slow are synonyms defined as:

Other synonyms of slow up include decelerate, retard, slow down.

As verbs, slow is a hyponym of slow up; that is, slow is a word with a more specific, narrower meaning than slow up:

Other hyponyms of slow up include slow down, slow up, delay, detain, hold up.

As verbs, slow up and slow are synonyms defined as:

Other synonyms of slow up include slow down.

As verbs, slow is a hypernym of slow up; that is, slow is a word with a broader meaning than slow up:

Other hypernyms of slow up include decelerate, retard, slow down, slow up.

As verbs, slow up and slow are synonyms defined as:

Other synonyms of slow up include slack, slacken, slow down.

slow up (adjective)	slow (adjective)
	not moving quickly; taking a comparatively long time
	at a slow tempo
	(used of timepieces) indicating a time earlier than the correct time
	(of business) not active or brisk
	slow to learn or understand; lacking intellectual acuity
	so lacking in interest as to cause mental weariness

slow up (verb)	slow (verb)
lose velocity; move more slowly	lose velocity; move more slowly
cause to proceed more slowly	become slow or slower
become slow or slower	cause to proceed more slowly

slow up (adverb)	slow (adverb)
	without speed (`slow' is sometimes used informally for `slowly')
	showing a time that is earlier than the actual time