Jack ups are simply trousers that are too short. There are at least 2-3 cm above your ankles.
Example 1 :

Your trousers are serious jack ups.(only if it is really visible that they are above your ankles)
Example 2:

Look at them jack ups, they are too LOL
by Itz_cutequeen October 13, 2017
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Used commonly in bridal TV programmes to describe adding accessories to enhance the look. When a bride finds a dress that she likes, the consultant may offer to jack her up, meaning to add all the accessories like tiara and veil so that she can visualise how she may look on her wedding day.
Bride-to-be: I love this wedding dress.
Consultant: Would you like to see it jacked up?
by FireflyScotland May 22, 2021
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Something EXTREMELY, messed up.
Something that is so messed up that it deserves to have a ridiculous description.
That car is jacked up.... like a jacked up, jacked up penguin!
by Sterling1235 June 14, 2016
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