To 'razz'
something is to use something for it's intended way, but in a cool and or stylish fashion, usually done in a slap-dash, playful manner, usually for a short amount of time for a quick
practical or language based gag.
i.e, 'having a razz with a girl/man' would refer to having enjoyable, good sex with a partner or 'having a razz on my guitar' can be
translated into 'I quickly played my guitar'.