Glad rags of use to show people (8)
I believe the answer is:
laggards
'people' is the definition.
(laggard is a kind of person)
'glad rags of use' is the wordplay.
'of use' indicates anagramming the letters (I've seen 'using' mean this (the letters used in a different way)).
'glad'+'rags'='gladrags'
'gladrags' anagrammed gives 'LAGGARDS'.
'to show' acts as a link.
(Other definitions for laggards that I've seen before include "Dawdlers" , "They tend to fall behind" , "Slow people; glad rags (anag.)" , "They make slow progress and fall behind others" .)